The Engine Scan Tool Data Definitions contains a brief description of all engine related parameters available on the scan tool. The list is arranged in alphabetical order. A given parameter may appear in any one of the data lists. In some cases, the parameter may appear more than once or in more than one data list in order to group certain related parameters together.

5-Volt Reference 1: This parameter displays the voltage sensed on the 5-volt reference 1 circuit at the control module. The scan tool will display a higher value at higher voltage. The scan tool will display a lower value at lower voltage.

5-Volt Reference 1 Circuit Status: This parameter will display OK if the circuit is good or Fault if a short to ground, short to B+ or open circuit is present.

5-Volt Reference 2: This parameter displays the voltage sensed on the 5-volt reference 2 circuit at the control module. The scan tool will display a higher value at higher voltage. The scan tool will display a lower value at lower voltage.

5-Volt Reference 2 Circuit Status: This parameter will display OK if the circuit is good or Fault if a short to ground, short to B+ or open circuit is present.

Air Flow Calculated: This parameter displays the air flow of the engine as calculated by the control module using information from the manifold absolute pressure (MAP) sensor. The scan tool will display a range of values indicating a high air flow when MAP pressure is high and a low air flow when MAP pressure is low. This value is listed in grams per second (g/s).

Ambient Air Temperature: Outside temperature at any given altitude expressed in degrees.

APP Indicated Angle: This parameter displays the angle of the accelerator pedal as calculated by the control module using the signals from the accelerator pedal position sensors. The APP indicated angle is a range of values indicating a low percentage when the accelerator pedal is not depressed to a high percentage when the accelerator pedal is fully depressed.

APP Sensor 1: This parameter displays the voltage signal sent to the control module from accelerator pedal position (APP) sensor 1 of the APP sensor assembly. APP sensor 1 is a range of values indicating a low voltage when the accelerator pedal is not depressed to a high voltage when the accelerator pedal is fully depressed.

APP Sensor 1 Indicated Angle: This parameter displays the angle of the APP sensor 1 as calculated by the control module using the signal from the APP sensor 1. APP sensor 1 is a range of values indicating a low percentage when the accelerator pedal is not depressed to a high percentage when the accelerator pedal is fully depressed.

APP Sensors 1 and 2: This parameter displays the results of a control module test that compares the signals from the accelerator pedal position (APP) sensors 1 and 2 . The scan tool will display Agree or Disagree. Agree indicates that APP sensor 1 and APP sensor 2 voltages correspond to the same accelerator pedal position. Disagree indicates that APP sensor 1 and APP sensor 2 voltages correspond to different accelerator pedal positions.

APP Sensor 2: This parameter displays the voltage signal sent to the control module from accelerator pedal position (APP) sensor 2 of the APP sensor assembly. APP sensor 2 is a range of values indicating a low voltage when the accelerator pedal is not depressed to a high voltage when the accelerator pedal is fully depressed.

APP Sensor 2 Indicated Position: This parameter displays the angle of the APP sensor 2 as calculated by the control module using the signal from the APP sensor 2. APP sensor 2 is a range of values indicating a low percentage when the accelerator pedal is not depressed to a high percentage when the accelerator pedal is fully depressed.

APP Sensors: This parameter displays the average of the accelerator pedal position (APP) sensors as calculated by the throttle actuator control (TAC) module. The APP average is a range of values indicating a low number when the accelerator pedal is not depressed to a high number when the accelerator pedal is fully depressed. This value is listed in percent.

BARO: This parameter displays the barometric pressure as calculated by the control module using the signal from the manifold absolute pressure (MAP) sensor measured when the ignition is turned on with the engine not running. The control module will update the barometric pressure during wide-open throttle (WOT) conditions.

Calc. TWC Temp.: Calculated catalytic converter temperature.

Catalyst Monitor Complete This Ignition: This parameter displays the monitor completion status during the current driving/monitoring cycle.

Catalyst Monitor Enabled This Ignition: This parameter displays the monitor enable status during the current driving/monitoring cycle.

Catalytic Converter Protection Active: This parameter displays the state of the Catalytic Converter Protection mode.

CKP Active Counter: This parameter displays an incrementing counter when the control module receives a signal from the crankshaft position (CKP) sensor.

CKP Resync Counter: This parameter displays the number of times the control module has to resynchronize the CKP sensor, per drive cycle.

CKP Sensor: This parameter displays the engine speed as calculated by the control module using the signal from the CKP sensor.

Cmmd. A/F Equivalence Ratio: Equivalence numbers greater than one represent excess fuel in the fuel air mix. Equivalence numbers less than one represent a deficiency of fuel in the fuel air mix for complete combustion. The equivalence ratio will be reported as one when the vehicle is in Closed Loop.

CMP Active Counter: This parameter displays an incrementing counter when the control module receives a signal from the camshaft position (CMP) sensor.

CMP Sensor: This parameter displays the speed of the engine as calculated by the signal from the camshaft position (CMP) sensor .

Cold Startup: This parameter displays whether the engine meets the conditions for a cold startup during the present ignition cycle. The scan tool displays Yes when the conditions for a cold startup are met during this ignition cycle. The scan tool displays No when the conditions for a cold startup are not met during the present ignition cycle. Conditions for a cold startup require the coolant temperature and the intake air temperature to be below a predetermined temperature and within a certain range of each other. These conditions must occur after the engine was warmed up to a specific temperature during the previous ignition cycle.

Cycles Of Misfire Data: This parameter displays the number of cylinder firing events that were recorded as misfires as determined by the control module.

Cylinder 1 and 4 IC Circuit Status: This parameter displays the status of the output driver for the ignition control circuits. The scan tool will display OK if the circuit is operating correctly. The scan tool will display Fault if there is an open, short to ground or a short to voltage on the circuit.

Cylinder 2 and 5 IC Circuit Status: This parameter displays the status of the output driver for the ignition control circuits. The scan tool will display OK if the circuit is operating correctly. The scan tool will display Fault if there is an open, short to ground or a short to voltage on the circuit.

Cylinder 3 and 6 IC Circuit Status: This parameter displays the status of the output driver for the ignition control circuits. The scan tool will display OK if the circuit is operating correctly. The scan tool will display Fault if there is an open, short to ground or a short to voltage on the circuit.

Cylinder 1-6 Injector Circuit Status: This parameter displays the current status of the output driver for the injector control circuit. The scan tool will display OK if the circuit is operating correctly. The scan tool will display Fault if there is an open, short to ground or a short to voltage on the circuit.

Decel. Fuel Cutoff: This parameter displays the status of the operating mode used to turn off the fuel injectors during certain deceleration conditions. When the scan tool displays Active, the control module has turned off the fuel injectors. When the scan tool displays Inactive, the fuel system is operating normally.

Desired EGR Position: This parameter displays the position of the exhaust gas recirculation (EGR) valve commanded by the control module. The scan tool will display percent and voltage.

Desired Idle Speed: This parameter displays the engine idle speed in RPM commanded by the control module. The control module compensates for various engine loads in order to maintain the desired engine RPM at idle. This parameter is not valid unless the engine is running.

Distance Since DTC Cleared: This parameter displays the distance accumulated since an emission diagnostic trouble code was cleared. The scan tool will display increasing distance as the vehicle is driven.

EC Ignition Relay Command: This parameter displays the commanded state of the EC Ignition relay control circuit. The scan tool will display ON or OFF. ON indicates the EC ignition relay control circuit is being grounded by the control module, allowing voltage to other control module circuits and systems. OFF indicates the EC ignition relay is not being commanded on by the control module.

EC Ignition Relay Feedback Signal: This parameter displays the voltage signal sent to the control module from the engine control ignition relay. The scan tool will display battery voltage when the engine is running. The scan tool will display no voltage when the relay is OFF.

ECT Sensor: This parameter displays the temperature of the engine coolant based on the input from the engine coolant temperature sensor. When the coolant temperature is low, the scan tool will display a low temperature. When the coolant temperature is high, the scan tool will display a high temperature.

EGR Flow Test Count: Indicates the number of EGR flow test samples collected during the current ignition cycle. The maximum number of samples allowed is one during normal operation. If the PCM battery feed has been disconnected or a DTC P0401 has been cleared, 10 EGR flow test samples will be allowed during the next ignition cycle. This is to allow repair verification during a single ignition cycle.

EGR Learned Minimum Position: The scan tool displays 0-5.0 volts. This display represents the voltage that the PCM uses in order to determine whether or not the EGR valve is closed. The voltage displayed will be the closed position of the EGR pintle learned by the PCM. Represents the learned voltage that the PCM uses to determine whether or not the EGR valve is fully closed, 0 percent pintle position. If the EGR pulse width modulation (PWM) is 0 percent and a difference of more than 0.4 volts between EGR Feedback and EGR closed valve pintle position is detected an EGR DTC will set.

EGR Monitor Complete This Ignition: This parameter displays the diagnostic monitor completion status during the current driving/monitoring cycle.

EGR Monitor Enabled This Ignition: This parameter displays the diagnostic monitor enable status during the current driving/monitoring cycle.

EGR Position Sensor: This parameter displays the voltage from the exhaust gas recirculation (EGR) valve position sensor. This information provides the control module with the exact position of the EGR valve pintle. When the EGR valve is closed, the scan tool will display a low voltage. When the EGR valve is open, the scan tool will display a high voltage.

EGR Position Sensor: This parameter displays the position of the exhaust gas recirculation (EGR) valve pintle in percent. The scan tool will display 0 percent when the EGR valve is closed. The scan tool will display 100 percent when the EGR valve is fully open.

EGR Position Variance: This parameter displays the difference between the desired EGR valve position and the actual EGR position. The scan tool will display this difference in percent. Scan tool range 0 percent to 100 percent. displays the difference between Desired EGR Position and actual EGR Position currently being monitored by the PCM. If the EGR Position Error reaches an unacceptable level, an EGR DTC will set.

EGR Solenoid Command: This parameter displays the duty cycle commanded by the control module for the EGR valve in percent. The scan tool will display a high percentage when the EGR valve is commanded open. The scan tool will display a low percentage when the EGR valve is commanded closed. The scan tool range is 0 percent to 100 percent. The exhaust gas recirculation (EGR) duty cycle specifies the EGR valve on (valve open) time rate within a certain set cycle. Zero percent means that the valve is completely closed while a 100 percent is a fully open valve.

Engine Load: This parameter displays the engine load in percent based on inputs to the control module from various engine sensors. The scan tool will display a low percentage when the engine is at idle with little or no load. The scan tool will display a high percentage when the engine is running at a high RPM under a heavy load.

Engine Oil Pressure Switch: This parameter displays the state of the engine oil pressure as determined by the control module. The control module monitors the engine oil pressure switch to determine if the engine oil pressure is sufficient. The scan tool will display low when the engine oil pressure is below a predetermined value. The scan tool displays OK or Low. This parameter displays whether or not sufficient engine oil pressure is present.

Engine Run Time: This parameter displays the time elapsed since the engine was started. The scan tool will display the time in hours, minutes and seconds. The engine run time will reset to zero when the engine stops running.

Engine Speed: This parameter displays the speed of the crankshaft as determined by the control module using an input from the crankshaft position (CKP) sensor. The scan tool will display a high value at high engine speeds and a low value at low engine speeds.

EVAP Fault History: This parameter displays the result of the EVAP system diagnostic. Scan tool displays NO FAULT, EXCESS VACUUM, PURGE VALVE LEAK, SMALL LEAK, or WEAK VACUUM. The EVAP Fault History indicates the status of EVAP system diagnostics performed by the PCM.

EVAP Monitor Complete This Ignition: This parameter displays the diagnostic monitor completion status during the current driving/monitoring cycle.

EVAP Monitor Enabled This Ignition: This parameter displays the diagnostic monitor enable status during the current driving/monitoring cycle.

EVAP Purge Solenoid Circuit History: This parameter displays the diagnostic state history of the output driver for the EVAP Purge Solenoid circuit. The scan tool will display OK if the circuit is operating correctly. The scan tool will display Low/Open if there is an open or short to ground on the injector circuit. The scan tool will display High if there is a short to voltage on the injector circuit.

EVAP Purge Solenoid Circuit Status: This parameter displays the status of the output driver for the evaporative emission purge solenoid control circuit. The scan tool will display OK if the circuit is operating correctly. The scan tool will display Fault if there is an open, short to ground or a short to voltage on the circuit.

EVAP Purge Solenoid Command: This parameter displays the on-time or duty cycle of the evaporative emission (EVAP) purge solenoid commanded by the control module expressed as a percent. The scan tool will display a high percentage when the control module is commanding the EVAP purge solenoid to be open a large amount . The scan tool will display a low percentage when the control module is commanding the EVAP purge solenoid to be open a small amount. The scan tool will display 0 when the control module is commanding the EVAP purge solenoid closed.

EVAP Vent Solenoid Command: This parameter displays the state of the evaporative emission (EVAP) vent solenoid commanded by the control module expressed as a Venting or Not Venting. The scan tool will display a venting when the control module is commanding the EVAP vent solenoid to be open . The scan tool will display a not venting when the control module is commanding the EVAP vent solenoid to be closed.

Fuel Level Sensor: This parameter displays the approximate fuel level in the fuel tank as a voltage. The control module calculates this level using the signal from the sensor used to monitor the fuel level in the fuel tank. The scan tool will display a low reading when the fuel level in the tank is low or near empty. The scan tool will display a high reading when the fuel level in the tank is high or near full.

Fuel Pump Relay Command: This parameter displays the commanded state of the fuel pump relay control circuit. The fuel pump relay should be on when the scan tool indicates the Fuel Pump Relay Command is On. The fuel pump relay should be off when the scan tool indicates the Fuel Pump Relay Command is Off.

Fuel Tank Level Remaining: This parameter displays the amount of fuel remaining in the fuel tank as a percentage. The control module calculates this level using the signal from the sensor used to monitor the fuel level in the fuel tank. The scan tool will display a low reading when the fuel level in the tank is low or near empty. The scan tool will display a high reading when the fuel level in the tank is high or near full.

Fuel Tank Pressure Sensor: This parameter displays the fuel tank pressure as calculated based on a signal sent to the control module from the fuel tank pressure (FTP) sensor. The scan tool will display a low value when the pressure in the fuel tank is low or a vacuum. The scan tool will display a high value when the pressure in the fuel tank is high.

Fuel Tank Rated Capacity: This parameter displays the rated maximum quantity of fuel the fuel tank will hold. This is calibrated in the control module to match the vehicle.

Fuel Trim Cell: This parameter displays the fuel trim cell number as calculated by the control module based on engine speed and load inputs. The scan tool will display a lower number as conditions are nearer to idle, and a higher value as conditions approach maximum engine speed and maximum load.

Fuel Trim Learn: This parameter indicates if the control module is adjusting long term fuel trim in response to the short term fuel trim. The scan tool displays Enabled or Disabled. When conditions are appropriate for enabling long term fuel trim corrections, the scan tool displays Enabled.

Fuel Trim System Test State: This parameter indicates the status of the Fuel Trim System Test. The scan tool will display Disabled, Enabled, Monitoring, or Run Purge Test.

Fuel Volatility: This parameter indicates the rate the fuel can be vaporized in the cylinder as calculated by the control module. The scan tool displays Low, Moderate, or High. The scan tool will display HIGH when the fuel volatility is high. The scan tool will display LOW when the fuel volatility is low.

HO2S 1: The scan tool displays mV. The scan tool displays a range of 0-1,106 mV. The HO2S 2 parameter represents the exhaust oxygen sensor output voltage. The voltage fluctuates constantly within a range between 10 mV , and 1,000 mV, while operating in Closed Loop. The scan tool displays 0 to 1275 mV. This parameter is the actual voltage on the HO2S signal circuit as measured by the ECM.

HO2S 2: This parameter indicates the heated oxygen sensor (HO2S) output voltage as measured by the control module. The scan tool will display a higher value during rich running conditions, and a lower value during leaner running conditions. The post-catalyst HO2S output voltage will fluctuate slowly over a longer period of time, compared to the fuel control oxygen sensor. This is due to the oxygen storage capacity of an efficiently operating catalyst. The scan tool displays 0 to 1275 mV. This parameter is the actual voltage on the heated oxygen sensor (HO2S) signal circuit as measured by the control module.

HO2S 1 Heater: This parameter displays the current through the control module when the HO2S heater is commanded ON by the control module. HO2S Heater Sen. 1 is a range of values indicating a low current when the heater circuit resistance is high to a high current when the heater circuit resistance is low.

HO2S 1 Heater Circuit Status: This parameter displays the status of the output driver for the HO2S Heater Sensor 1. The scan tool will display OK if the circuit is operating correctly or Incomplete if the test result has not been determined. The scan tool will display open, short to ground or, short to voltage if a fault exists on the circuit.

HO2S 1 Heater Command: This parameter displays the commanded state of the heater control circuit for oxygen sensor 1. The oxygen sensor heater should be on when the scan tool indicates the HO2S Heater Command is On. The oxygen sensor heater should be off when the scan tool indicates the HO2S Heater Command is Off.

HO2S 1 Heater Command: This parameter displays the commanded state of the HO2S heater by the control module. The scan tool will display a higher percentage as the heater command is increased, and a lower percentage if the heater is not commanded ON.

HO2S 2 Heater: This parameter displays the current through the control module when the HO2S heater is commanded ON by the control module. HO2S Heater Sen. 1 is a range of values indicating a low current when the heater circuit resistance is high to a high current when the heater circuit resistance is low.

HO2S 2 Heater Circuit Status: This parameter displays the status of the output driver for the HO2S Heater Sensor 2. The scan tool will display OK if the circuit is operating correctly or Incomplete if the test result has not been determined. The scan tool will display open, short to ground or, short to voltage if a fault exists on the circuit.

HO2S 2 Heater Command: This parameter displays the commanded state of the heater control circuit for oxygen sensor 1. The oxygen sensor heater should be on when the scan tool indicates the HO2S Heater Command is On. The oxygen sensor heater should be off when the scan tool indicates the HO2S Heater Command is Off.

HO2S 2 Heater Command: This parameter displays the commanded state of the HO2S heater by the control module. The scan tool will display a higher percentage as the heater command is increased, and a lower percentage if the heater is not commanded ON.

HO2S Heater Monitor Complete This Ignition: This parameter displays the diagnostic monitor completion status during the current driving/monitoring cycle.

HO2S Heater Monitor Enabled This Ignition: This parameter displays the diagnostic monitor enable status during the current driving/monitoring cycle.

HO2S/O2S Monitor Complete This Ignition: This parameter displays the diagnostic monitor completion status during the current driving/monitoring cycle.

HO2S/O2S Monitor Enabled This Ignition: This parameter displays the diagnostic monitor enable status during the current driving/monitoring cycle.

HOT Open Loop: This parameter indicates the status of the fuel delivery system. The scan tool will display Active if the fuel system is running in open loop due to a temperature concern. The scan tool will display Inactive if the fuel system is operating normally.

IAT Sensor: The scan tool displays °C. The PCM converts the resistance of the intake air temperature (IAT) sensor to degrees in the same manner as the ECT sensor. Intake air temp is used by the PCM to adjust fuel delivery and spark timing according to incoming air density. The scan tool displays a range of -39 to 140°C (-38 to +284°F). The PCM converts the resistance of the intake air temperature sensor to degrees. The PCM uses the IAT in order to adjust fuel delivery and spark timing according to incoming air density.

Ignition 1 Signal: This parameter displays the voltage measured at the ignition 1 circuit of the control module. Voltage is applied to the control module when the ignition switch is in the ignition 1 position.

Ignition Accessory Signal: This parameter displays the state of the ignition 0 input to the control module from the ignition switch. The scan tool will display On when the ignition switch is in the ignition accessory position. The scan tool will display Off when the ignition switch is in any other position.

Ignition Off Time: The Scan tool displays time in minutes. This parameter is used by the control module to identify the amount of time that has passed. This parameter is used for various components and systems including TAC system and the EVAP system.

Inj. 1 Disabled Due to Misfire: This parameter displays the status of the fuel injector driver by the control module. The scan tool will display YES if the fuel injector is being disabled due to a misfire detection. The scan tool will display NO if the fuel injector is not being disabled by the control module due to a misfire.

Inj. 2 Disabled Due to Misfire: This parameter displays the status of the fuel injector driver by the control module. The scan tool will display YES if the fuel injector is being disabled due to a misfire detection. The scan tool will display NO if the fuel injector is not being disabled by the control module due to a misfire.

Inj. 3 Disabled Due to Misfire: This parameter displays the status of the fuel injector driver by the control module. The scan tool will display YES if the fuel injector is being disabled due to a misfire detection. The scan tool will display NO if the fuel injector is not being disabled by the control module due to a misfire.

Inj. 4 Disabled Due to Misfire: This parameter displays the status of the fuel injector driver by the control module. The scan tool will display YES if the fuel injector is being disabled due to a misfire detection. The scan tool will display NO if the fuel injector is not being disabled by the control module due to a misfire.

Inj. 5 Disabled Due to Misfire: This parameter displays the status of the fuel injector driver by the control module. The scan tool will display YES if the fuel injector is being disabled due to a misfire detection. The scan tool will display NO if the fuel injector is not being disabled by the control module due to a misfire.

Inj. 6 Disabled Due to Misfire: This parameter displays the status of the fuel injector driver by the control module. The scan tool will display YES if the fuel injector is being disabled due to a misfire detection. The scan tool will display NO if the fuel injector is not being disabled by the control module due to a misfire.

Injector PWM: The scan tool displays mS. Indicates the base pulse width modulation (PWM) or ON time of the fuel injectors in milliseconds. When the engine load is increased, the injector pulse width will increase. Indicates the amount of time the PCM is commanding each injector ON during each engine cycle. A longer injector pulse width will cause more fuel to be delivered. Injector pulse width should increase with increased engine load.

Intake Manifold Pressure: This parameter displays the pressure difference between the MAP and the barometric pressure (BARO) as calculated by the control module. The scan tool will display a higher value during high vacuum conditions, such as idle or deceleration. The scan tool will display a lower value during low vacuum conditions, such as wide open throttle or high load cruising.

Knock Detected Cyl. 1: This parameter displays the status of each cylinder for knock detection by the control module. The scan tool will display YES if a knock condition has been detected related to that cylinder combustion event. The scan tool will display NO if there is no knock condition detected related to that cylinder combustion event.

Knock Detected Cyl. 2: This parameter displays the status of each cylinder for knock detection by the control module. The scan tool will display YES if a knock condition has been detected related to that cylinder combustion event. The scan tool will display NO if there is no knock condition detected related to that cylinder combustion event.

Knock Detected Cyl. 3: This parameter displays the status of each cylinder for knock detection by the control module. The scan tool will display YES if a knock condition has been detected related to that cylinder combustion event. The scan tool will display NO if there is no knock condition detected related to that cylinder combustion event.

Knock Detected Cyl. 4: This parameter displays the status of each cylinder for knock detection by the control module. The scan tool will display YES if a knock condition has been detected related to that cylinder combustion event. The scan tool will display NO if there is no knock condition detected related to that cylinder combustion event.

Knock Detected Cyl. 5: This parameter displays the status of each cylinder for knock detection by the control module. The scan tool will display YES if a knock condition has been detected related to that cylinder combustion event. The scan tool will display NO if there is no knock condition detected related to that cylinder combustion event.

Knock Detected Cyl. 6: This parameter displays the status of each cylinder for knock detection by the control module. The scan tool will display YES if a knock condition has been detected related to that cylinder combustion event. The scan tool will display NO if there is no knock condition detected related to that cylinder combustion event.

Knock Retard: The scan tool displays degrees. Indicates the amount of spark the PCM is removing from IC spark advance in response to the signal from the knock sensors. The traction control system desired torque signal from the EBTCM may cause knock retard to display a value more than 0.0 degrees if traction control is active.

Long Term FT: The scan tool range is -99 to 99 percent . This parameter indicates the Long Term FT correction as commanded by the PCM. A change made to the fuel delivery will be indicated by the Long and Short Term FT values. The Short Term FT values change rapidly in response to the HO2S signal voltages. These changes fine tune the engine fueling. The Long Term FT values change in response to the trends in the Short Term FT. The Long Term FT makes coarse adjustments to the fueling in order to re-center and restore control to the Short Term FT. The Short Term FT and the Long Term FT can be monitored with a scan tool. A positive fuel trim value indicates that the ECM is adding fuel in order to compensate for a lean condition. A negative fuel trim value indicates that the ECM is reducing the amount of fuel in order to compensate for a rich condition.

Loop Status: Closed loop indicates that the PCM is controlling fuel delivery according to oxygen sensor voltage. In open loop, the PCM ignores the oxygen sensor voltage and bases the amount of fuel to be delivered on throttle position (TP) sensor, engine coolant temperature (ECT), and MAF sensor inputs only.

LT FT Test Avg.: This parameter is the average long term fuel trim for this bank as calculated by the control module. The scan tool will display a value more than 0 percent indicating that time is being added to the injector pulse width, increasing the amount of fuel to the engine. The scan tool will display a value of less than 0, indicating time is being subtracted from the injector pulse width, reducing the amount of fuel to the engine. A value of 0 percent indicates no compensation is required to operate the engine at the desired air/fuel ratio.

LT FT Test Avg. w/o purge: This parameter is calculated by the control module based on the Short Term FT value. The Long Term FT is used for the long term correction of the fuel delivery. The scan tool will display a high value for a large amount of long term fuel correction, and 0% for no long term fuel trim correction. The scan tool will display a negative value when fuel system is running too rich and fuel is being removed from the combustion event. The scan tool will display a positive value if the fuel system is running lean and fuel is being added to the combustion event

MAF Performance Test: This parameter displays the status of the mass air flow (MAF) performance test by the control module. The scan tool will display OK if no fault is found. The scan tool will display Fault if the control module detects a fault during the test.

MAF Sensor: The scan tool displays g/s. The scan tool displays a range of 0.0-655 g/s. The mass air flow (MAF) is the MAF input frequency converted to grams of air per second. This indicates the amount of air entering the engine.

MAF Sensor: The scan tool displays a range of 0-31,999 Hz. The MAF sensor is a hot wire type air flow sensor. The PCM converts current draw needed by the MAF to keep the hot wires at a constant into a frequency signal. The scan tool displays this frequency in a hertz signal.

MAP Sensor Performance Test 1: This parameter displays the status of the MAP performance test 1 by the control module. The scan tool will display OK if no fault is found. The scan tool will display Fault if the control module detects a fault during the test.

MAP Sensor Performance Test 2: This parameter displays the status of the MAP performance test 2 by the control module. The scan tool will display OK if no fault is found. The scan tool will display Fault if the control module detects a fault during the test.

MAP Sensor: The scan tool displays kPa. The manifold absolute pressure (MAP) sensor measures the change in the intake manifold pressure which results from engine load and speed changes. As the intake manifold pressure increases, the air density in the intake also increases and additional fuel is required. The scan tool displays a range of 10-105 kPa. The MAP sensor measures the absolute pressure in the intake manifold.

MAP Sensor: The scan tool displays Volts. The manifold absolute pressure (MAP) sensor measures the change in the intake manifold pressure which results from engine load and speed changes. As the intake manifold pressure increases, the air density in the intake also increases and additional fuel is required. The scan tool displays a range of 10-105 kPa. The MAP sensor measures the absolute pressure in the intake manifold.

MIL Command: This parameter displays the commanded state of the malfunction indicator lamp (MIL) control circuit. The malfunction indicator lamp should be on when the scan tool indicates the MIL Command is On. The malfunction indicator lamp should be off when the scan tool indicates the MIL Command is Off. The control module will command the MIL On when the ignition is ON with the engine OFF in order to perform a bulb check.

MIL Requested by DTC: This parameter shows if the illumination of the MIL has been requested by a failed diagnostic trouble code (DTC).

Misfire Current Cyl. 1-6: The scan tool displays 0-255 counts. The display shows the number of misfires that have been detected during the last 200 cylinder firing events. The counters may normally display some activity, but the activity should be nearly equal for all of the cylinders, and in low numbers.

Misfire History Cyl. 1-6: The scan tool range is 0-255 counts. This parameter indicates the total level of misfire that has been detected on each cylinder. The misfire history counters will not update or show any activity until a misfire or DTC P0300 has become active. The misfire history counter will update every 200 cylinder firing events.

Power Enrichment: Scan tool displays ACTIVE or INACTIVE. ACTIVE displayed indicates that the PCM has detected conditions appropriate to operate in Power Enrichment mode. The PCM will command Power Enrichment mode when a large increase in throttle position and load is detected. While in Power Enrichment, the PCM will increase the amount of fuel delivered by entering Open Loop and increasing the injector pulse width. This is done to prevent a possible sag or hesitation from occurring during acceleration.

Reduced Engine Power: The scan tool displays Active or Inactive. The scan tool displays Active when the PCM receives a signal from the TAC module that a throttle actuator control system fault is occurring. The PCM limits the engine power.

Short Term FT:  The Short Term FT values change rapidly in response to the HO2S signal voltages. These changes fine tune the engine fueling. The Long Term FT values change in response to the trends in the Short Term FT. The Long Term FT makes coarse adjustments to the fueling in order to re-center and restore control to the Short Term FT . The Short Term FT and the Long Term FT can be monitored with a scan tool. A positive fuel trim value indicates that the ECM is adding fuel in order to compensate for a lean condition. A negative fuel trim value indicates that the ECM is reducing the amount of fuel in order to compensate for a rich condition.

Spark: The scan tool displays a range of -64 degrees to +64 degrees. The scan tool displays the amount of degrees the PCM commands. The PCM computes the desired spark advance using the following: (1) engine coolant temperature (ECT), (2) engine speed (RPM), (3) load, (4) vehicle speed. The PCM adjusts the timing. A negative (-) value indicates degrees before top dead center (BTDC) or spark advance; a positive value indicates degrees after top dead center (ATDC) or spark retard.

ST FT Test Avg.: This parameter is calculated by the control module based on an intrusive test by the control module. The Short Term FT Test Average used for the short term correction of the fuel delivery. The scan tool will display a high value for a large amount of short term fuel correction, and 0% for no short term fuel trim correction. The scan tool will display a negative value when fuel system is running too rich and fuel is being removed from the combustion event. The scan tool will display a positive value if the fuel system is running lean and fuel is being added to the combustion event.

Start Up ECT: Indicates the engine coolant temperature at engine start up. The scan tool displays a range of -39 to +140°C (-38 to +284°F). The scan tool displays the engine ECT at the time the engine was started. The PCM uses start-up ECT for certain DTCs. Indicates the engine coolant temperature at the time that the vehicle was started. Used to determine if the last startup was a cold start.

Start Up IAT: Indicates the intake air temperature (IAT) at the time that the vehicle was started. Used to determine if the last startup was a cold start. The scan tool range is -39 to +140°C (-38 to +284°F). This parameter indicates the ambient air temperature at start-up.

TAC Forced Engine Shutdown: This parameter indicates the status of TAC control by the control module. The scan tool will display YES if the engine has been shut down due to a throttle control fault. The scan tool will display NO if the engine has not been shut down by a throttle control fault.

TAC Motor: This parameter indicates the status of the TAC motor driver by the ECM. The scan tool will display Enabled if TAC motor operation is allowed. The scan tool will display disabled if the TAC motor is disabled.

TAC Motor Command: This parameter indicates the required duty cycle to maintain a desired throttle position. The scan tool will display a higher value if more effort is required to move the throttle to the desired position, such as physical resistance. The scan tool will display a lower value if less effort is required to move the throttle to the desired position.

Torque Management Spark Retard: This parameter indicates how much the ignition spark timing is being retarded to control torque by the control module. The scan tool will display a higher value under extreme torque control conditions such as spinning wheels. The scan tool will display a lower value under low torque control conditions such as light driving.

Total Knock Retard: This parameter indicates how much ignition spark timing is being retarded due to all control systems monitored by the control module. The scan tool will display a high value during extreme conditions such as high temperatures and antilock braking. The scan tool will display a lower value during lighter driving conditions.

Total Misfire: The scan tool range is 0-255 counts. This parameter indicates the total level of misfire that has been detected on each cylinder. The misfire history counters will not update or show any activity until a misfire or DTC P0300 has become active. The misfire history counter will update every 200 cylinder firing events.

TP Desired Angle: The scan tool displays %. The scan tool displays 0-100 percent. The PCM indicates the desired throttle angle commanded by the vehicle operator. The scan tool indicates the desired throttle angle commanded by the vehicle operator.

TP Indicated Angle: This parameter displays the angle of the throttle position (TP) in percent. This information is calculated by the control module using the signals from the Throttle position sensors. The scan tool will display a low percentage when the throttle plates are closed. The scan tool will display a high percentage when the throttle plates are fully open.

TP Performance Test: This parameter displays the status of the TP performance test by the control module. The scan tool will display OK if no fault is found. The scan tool will display Fault if the control module detects a fault during the test.

TP Sensor 1: This parameter displays the voltage signal sent to the control module from the sensor used to monitor the position of the throttle plates. This parameter is for sensor 1 of the throttle position (TP) sensor assembly. The scan tool will display a low voltage when the throttle plates are at rest. The scan tool will display a high voltage when the throttle plates are fully open.

TP Sensor 1 Indicated Position: This parameter displays the angle of the TP sensor 1 in percent. This information is calculated by the control module using the signal from the throttle position sensor 1. The scan tool will display a low percentage when the throttle plates are closed. The scan tool will display a high percentage when the throttle plates are fully open.

TP Sensor 1 Learned Minimum: This parameter displays the learned minimum voltage for TP sensor 1 as determined by the control module this ignition cycle.

TP Sensors 1 and 2: This parameter displays the results of a control module test that compares the signals from the TP sensors 1 and 2 . The scan tool will display Agree when the signal from TP sensor 1 corresponds with the signal from TP sensor 2. The scan tool will display Disagree when the signal from TP sensor 1 conflicts with the signal from TP sensor 2.

TP Sensor 2: This parameter displays the voltage signal sent to the control module from the sensor used to monitor the position of the throttle plates. This parameter is for sensor 2 of the TP sensor assembly. The scan tool will display a high voltage when the throttle plates are at rest. The scan tool will display a low voltage when the throttle plates are fully open.

TP Sensor 2 Indicated Position: This parameter displays the angle of the TP sensor 2 in percent. This information is calculated by the control module using the signal from the throttle position sensor 2. The scan tool will display a low percentage when the throttle plates are closed. The scan tool will display a high percentage when the throttle plates are fully open.

TP Sensor 2 Learned Minimum: This parameter displays the learned minimum voltage for TP sensor 2 as determined by the control module this ignition cycle.

Vehicle Speed Sensor: The scan tool range is 0-200 km/h (0-125 mph). This parameter displays the vehicle speed. The PCM receives reference pulses from the vehicle speed sensor (VSS) and converts them into km/h and mph for display.

Warm-ups Since DTC Cleared: This parameter counts the number of warm up cycles since the last diagnostic trouble code (DTC) was cleared from the controller memory.

Warm-ups w/o Emission Faults: The scan tool displays The scan tool displays a range of 0-255. This parameter counts the number of warm up cycles without an emission fault present. The counter increments to 255 and rolls back to 0 unless a fault occurs. If a fault occurs, the counter reverts back to 0 until the fault is corrected. Clearing the information with a scan tool or a loss of power to the PCM also resets the counter to 0. The scan tool displays counts. This display indicates the number of warm-up cycles without a emission failure.

Warm-ups w/o Non-Emission Faults: The scan tool displays The scan tool displays a range of 0-255. This parameter counts the number of warm-up cycles without a non-emission fault present. The counter increments to 255 and rolls back to 0 unless a fault occurs. If a fault occurs, the counter reverts back to 0 until the fault is corrected. Clearing information with a scan tool or a loss of power to the PCM also resets the counter to 0.

Wide Open Throttle: This parameter indicates the throttle status commanded by the control module. The scan tool will display YES is the vehicle throttle is commanded to wide open. The scan tool will display NO if the vehicle throttle is commanded to an amount less than 100%.