Not all parameters will apply to each vehicle. Use only the parameters which apply to your particular vehicle.

1-2 Solenoid-- (ON/OFF): The scan tool indicates whether this shift solenoid in the automatic transmission is commanded ON by the VCM.

2-3 Solenoid-- (ON/OFF): The scan tool indicates whether this shift solenoid in the automatic transmission is commanded ON by the VCM.

3-2 Downshift Solenoid-- (ON/OFF): The scan tool indicates whether this shift solenoid in the automatic transmission is commanded ON by the VCM.

4WD-- (Enable/Disable): The scan tool indicates enabled when four wheel drive has been selected by the operator.

4WD Low-- (Enable/Disable): The scan tool indicates enabled when four wheel drive low has been selected by the operator.

A/C Evaporator Switch--(Open/Closed): The A/C Evaporator Switch is an input to the VCM that determines when pressure has reached a calibrated threshold. The VCM uses this switch as the primary input for determining when to command the A/C compressor ON or OFF.

A/C Sec. High Pres. Switch-- (Open/Closed):  The Secondary High Press. Switch closes when the A/C systems high pressure limit is approached. The VCM monitors the state of this switch for compressor and auto recirculation operation. The switch closes at a high pressure value which is calibrated for specific platforms. The VCM continuously monitors the secondary high pressure switch when A/C has been selected by the operator.

A/C Relay-- (ON/OFF): The scan tool indicates whether the A/C relay control circuit has been commanded ON by the VCM. The A/C relay provides power to control the A/C compressor clutch. It will indicate YES when the relay is commanded ON.

A/C Request-- (Yes/No): The scan tool indicates the state of the A/C request input circuit. The VCM uses the A/C request signal in order to determine whether A/C compressor operation has been requested by the operator.

Actual EGR Position--Range (0-100%): The Actual EGR Position indicates the actual EGR valve pintle position as a percentage. A fully closed valve would be displayed as 0 percent.

Air Fuel Ratio--Range (0.0:1-25.5:1): The scan tool indicates the VCM calculated air to fuel ratio. The typical air to fuel ratio is 14.7:1.

Auto Recirculation-- (ON/OFF): If the Secondary High Pressure switch closes, indicating high refrigerant pressures, auto recirculation will be commanded ON by the VCM. This will prevent warm outside air from entering the vehicle which might further raise the A/C refrigerant pressures.

Barometric Pressure (BARO)--Range (0-5 Volts): The BARO represents a measurement of the barometric air pressure. This measurement is determined by using the manifold air pressure (MAP) sensor in order to determine manifold vacuum. This function is performed when the ignition is selected from OFF to ON, and during high throttle angle operations when manifold pressure equals ambient barometric pressure. This parameter is scaled in volts which is the raw output from the MAP sensor prior to being converted by the VCM to kPa.

Barometric Pressure (BARO)-- Range (62 kPa-104 kPa): The VCM calculates the displayed BARO parameter from the MAP sensor when the ignition is selected from OFF to ON and at WOT conditions. The BARO parameter represents local ambient barometric pressure. The VCM uses the displayed BARO reading in order to compensate engine fueling differences for changes in altitude. This parameter is scaled in kilo pascals (k/pa).

Brake Switch--Range (Applied/Released): The Brake Switch indicates the status of the brake switch. Applied would indicate the brake pedal has been depressed.

Closed Loop (CL) Since Restart-- (Yes/No): The Closed Loop Since Restart indicates whether or not the vehicle has been in a closed loop state during the current ignition cycle.

CMP Retard--Range (0-90 degrees): The CMP Retard indicates a correction to the CMP sensor and the CKP sensor relationship caused by small tolerance variations or component misalignment.

Cruise-- (Enable/Disable): The Cruise parameter indicates if the driver has requested cruise control.

Cycles of Misfire Data--Range (0-100): Displays an increasing count of crankshaft revolutions from 0 to 100. It will reset to 0 after reaching 100.

Decel Fuel Mode-- (Active/Inactive): The scan tool indicates whether the vehicle is in decel fuel cutoff mode. This mode is generally entered during long decels to prevent catalyst overheating and excessive tailpipe emissions.

Desired EGR Position--Range (0-100%): The Desired EGR Position indicates the desired EGR pintle position in a percentage. 0 percent indicates a closed EGR valve. 100 percent is a fully opened EGR valve.

Desired IAC Position--Range (0-255) Counts: The desired IAC Position indicates how much the IAC valve is commanded open by the VCM. 0 counts would indicate a commanded fully closed valve. 255 counts would indicate a commanded fully opened valve.

Desired Idle Speed--Range (0-3,187 RPM): The VCM commands the Desired Idle Speed by controlling the IAC. The VCM compensates for various engine loads by controlling IAC in order to maintain the desired idle speed.

DTC Set this Ignition-- (Yes/No): The scan tool indicates whether or not any DTC has set during the current ignition cycle.

ECT--Range (-40 to 215°C (-40 to 419°F): The engine coolant temperature (ECT) sensor is mounted in a coolant passage in the intake manifold. The VCM monitors the engine temperature as the ECT sensor responds to temperature changes in the engines coolant.

ECT Sensor--Range (0-5 Volts): The engine coolant temperature (ECT) sensor is mounted in a coolant passage in the intake manifold. The VCM monitors the engine temperature as the ECT sensor responds to temperature changes in the engines coolant. This parameter is scaled in volts and is the raw voltage from the ECT detected by the VCM on the signal circuit.

EGR Duty Cycle--Range (0-100%): The EGR Duty Cycle determines the percentage of time the EGR valves control circuit has 12 volts applied to it. This is a method to control the current applied to the valve motor. As duty cycle increases, so does current which forces the valve to open further and allow more exhaust gas to enter the intake. 100 percent duty cycle would indicate a fully opened valve.

EGR Sensor--Range (0-5 Volts): The EGR sensor indicates the actual EGR pintle position, as detected by the VCM, scaled in voltage. A low voltage indicates a closed valve.

Engine Load--Range (0-100%): The VCM determines the engine load based upon the engine speed and MAF sensor readings. Engine Load increases with any increase in RPM and/or airflow.

Engine Run Time--Range (0:00:00-18:12:15) Hours: Minutes: Seconds: The Engine Run Time is a measure of how long the engine has run during this ignition cycle. When the engine stops running, the timer resets to zero.

Engine Speed--Range (0-16,384 RPM): The VCM computes the engine speed from the CKP sensor input.

EVAP Canister Purge--(OFF/ON): The EVAP Canister Purge pulls a small vacuum on the entire evaporative emission system. The scan tool displays if the EVAP canister purge solenoid valve is currently OFF or ON. When the scan tool displays ON, manifold vacuum is being applied to the system.

EVAP Duty Cycle--Range (0-100%): The scan tool indicates the EVAP duty cycle that the VCM is commanding. The EVAP duty cycle is a pulse width modulated voltage applied to the purge valve which is displayed as a percentage. A high percentage of EVAP duty cycle would indicate near maximum canister purging.

EVAP Vent Solenoid-- (Closed/Open): The scan tool will show the status of the EVAP Vent Solenoid. A closed EVAP Vent Solenoid would indicate the Evaporative System is being tested for leaks.

Excess Vacuum Test-- (Pass/Not Run/Fail): The Excess Vacuum Test will Fail if fuel tank vacuum builds at an excessive rate during normal EVAP canister purge. A restricted vent valve or vent valve hoses will cause improper venting. The scan tool display states for this parameter are Pass and Not Run/Fail.

Fuel Level--Range (0-100%): The scan tool indicates as a percentage the level of fuel in the fuel tank. As the senders float position changes, the fuel level sensors signal voltage changes. The VCM converts this voltage into a percentage of fuel remaining in the fuel tank.

Fuel Level Sensor--Range (0-5 Volts): The scan tool will display the fuel level sensor signal voltage which varies with fuel level.

Fuel Tank Pressure--Range (-20 to 7 in H2O): The scan tool displays the vapor pressure measured in the fuel tank by the fuel tank pressure transducer. The VCM converts the raw voltage signal from the sensor into a pressure scale displayed by the scan tool.

Fuel Trim Cell--Range (0-22) Cell: 22 separate cells contain MAP and RPM values from a range of engine operating conditions. Each cell determines fuel requirements for a specific operating condition that the engine is running within. Examples would be idling, accelerations, road load cruise, or decelerations.

Fuel Trim Enable-- (YES/NO): This parameter indicates when the VCM is using fuel trim values to adjust fuel delivery to the engine. Fuel trim will be disabled when the vehicle is not in closed loop, malfunction codes related to fuel trim are set, large amounts of purge vapor are ingested by the engine, or additional diagnostics that temporarily affect fuel trim operation are active.

HO2S BN 1 Sen. 1--Range (0-1 Volts): The HO2S BN 1 Sen. 1 indicates the voltage activity of the HO2S (bank 1 sensor 1).

HO2S BN 1 Sen. 2--Range (0-1 Volts): The HO2S BN 1 Sen. 2 indicates the voltage activity of the HO2S (bank 1 sensor 2).

HO2S BN 1 Sen. 3--Range (0-1 Volts): The HO2S BN 1 Sen. 3 indicates the voltage activity of the HO2S (bank 1 sensor 3).

HO2S BN 2 Sen. 1--Range (0-1 Volts): The HO2S BN 2 Sen. 1 indicates the voltage activity of the HO2S (bank 2 sensor 1).

HO2S BN 2 Sen. 2--Range (0-1 Volts): The HO2S BN 2 Sen. 2 indicates the voltage activity of the HO2S (bank 2 sensor 2).

HO2S Xcounts Bn 1--Range (0-255): The HO2S Xcounts Bn 1 increments each time that the HO2S (bank 1 sensor 1) crosses the 450 MV threshold. This number resets to zero after it reaches it limit of 255.

HO2S Xcounts Bn 2--Range (0-255): The HO2S Xcounts B2 increments each time that the HO2S (bank 2 sensor 1) crosses the 450 MV threshold. This number resets to zero after it reaches it limit of 255.

IAC Position--Range (0-255) Counts: The scan tool displays in counts the idle air control (IAC) pintle position commanded by the VCM. The greater the number of counts, the larger the air passage opening. The idle air control should respond fairly quickly to changes in engine load in order to maintain desired idle RPM.

Intake Air Temperature (IAT)--Range (-40 to 151°C (-40 to 303°F): The VCM converts the signal voltage of the intake air temperature (IAT) sensor into degrees. The VCM uses the intake air temperature in order to adjust fuel delivery and spark timing according to the incoming air temperature.

Intake Air Temperature (IAT) Sensor--(0-5 Volts): The VCM monitors the intake air temperature (IAT) sensor for voltage changes. This parameter displays the raw voltage signal detected by the VCM. The VCM uses the intake air temperature in order to adjust fuel delivery and spark timing according to the incoming air temperature.

Ignition 1--Range (0.0-25.5 Volts): The Ignition 1 parameter indicates the voltage level on the ignition input to the VCM. The normal ignition 1 voltage is approximately 13.8 volts, but may vary between 11-16 volts.

Ignition 1 Low-- (Yes/No): The scan tool indicates when low ignition voltage has been detected by the VCM A low ignition 1 voltage may degrade ignition timing and injector operation. The normal ignition 1 voltage is approximately 13.8 volts, but may vary between 11-16 volts.

Ignition 1 High-- (Yes/No): The scan tool indicates when high ignition voltage has been detected by the VCM. An excessively high ignition 1 voltage could damage electronics and electrical components. The normal ignition 1 voltage is approximately 13.8 volts, but may vary between 11-16 volts.

Ignition 1 ON-- (Yes/No): The Ignition 1 On parameter indicates when the VCM is detecting ignition voltage. The normal ignition voltage is approximately 13.8 volts, but may vary between 11-16 volts. The VCM monitors the ignition voltage to compensate for low voltage operation of the injectors and to increase the dwell time of the ignition coil.

Inj. PWM Average Bank 1--Range (0-499 ms): The Inj. PWM Avg. bank 1 indicates the VCM commanded injector ON time, measured in milliseconds.

Inj. PWM Average Bank 2--Range (0-499 ms): The Inj. PWM Avg. bank 2 indicates the VCM commanded injector ON time, measured in milliseconds.

KS Adjust Factor--Range (-90 to 90°): The knock sensor is a piezoelectric device which detects vibration due to spark knock. The VCM monitors the knock sensor signal while it performs spark advance calculations. This allows the engine to operate at maximum spark advance with out spark knock to improve driveability and fuel economy. This parameter is the number of degrees

Knock Retard--Range (0.0-90 degrees): The KS Retard indicates the amount of spark advance the VCM is removing in order to control spark knock.

Knock (KS) Sensor--Range (4.5-5.0 Volts): The scan tool indicates the current knock sensor nominal voltage detected by the VCM. This parameter is not an indication of the level of spark knock.

Knock (KS) Sensor Activity--Range (0-255 Counts): The knock sensor Activity will display a randomly fluctuating number between 0 and 255 when the VCM detects spark knock. This random number will be unchanging when no knock is present.

Long Term Fuel Trim (FT) Bn 1--Range (0-255 Counts): The Long Term Fuel Trim (FT) is derived from the Short Term FT value. The VCM uses the Long Term FT for the long term correction of the fuel delivery. A value of 128 counts indicates that the fuel delivery requires no compensation to maintain a 14.7:1 air to fuel ratio. A value below 128 counts means that the fuel system is too rich and the fuel delivery is being reduced, requiring decreased injector pulse width. A value above 128 counts indicates that a lean condition exists. The VCM compensates by adding fuel, increasing the injectors pulse width.

Long Term Fuel Trim (FT) Bn 1--Range (Percentage of Compensation Required): The Long Term Fuel Trim (FT) is derived from the Short Term FT value. The VCM uses the Long Term FT for the long term correction of the fuel delivery. A value of 128 counts indicates that the fuel delivery requires no compensation to maintain a 14.7:1 air to fuel ratio. A value below 128 counts means that the fuel system is too rich and the fuel delivery is being reduced, requiring decreased injector pulse width. A value above 128 counts indicates that a lean condition exists. The VCM compensates by adding fuel, requiring increased injector pulse width. As fuel compensation is required, the difference between commanded Long Term FT and 128 counts will be displayed as a percentage.

Long Term Fuel Trim (FT) Bn 2--Range (0-255 Counts): The Long Term Fuel Trim (FT) is derived from the Short Term FT value. The VCM uses the Long Term FT for the long term correction of the fuel delivery. A value of 128 counts indicates that the fuel delivery requires no compensation to maintain a 14.7:1 air to fuel ratio. A value below 128 counts means that the fuel system is too rich and the fuel delivery is being reduced, requiring decreased injector pulse width. A value above 128 counts indicates that a lean condition exists. The VCM compensates by adding fuel, requiring increased injector pulse width.

Long Term Fuel Trim (FT) Bn 2--Range (Percentage of Compensation Required): The Long Term Fuel Trim (FT) is derived from the Short Term FT value. The VCM uses the Long Term FT for the long term correction of the fuel delivery. A value of 128 counts indicates that the fuel delivery requires no compensation to maintain a 14.7:1 air to fuel ratio. A value below 128 counts means that the fuel system is too rich and the fuel delivery is being reduced, requiring decreased injector pulse width. A value above 128 counts indicates that a lean condition exists. The VCM compensates by adding fuel, requiring increased injector pulse width. As fuel compensation is required, the difference between commanded Long Term FT and 128 counts will be displayed as a percentage.

Loop Status-- (Open Loop/Close Loop): The Loop Status indicates when the VCM is controlling fuel delivery which is calculated using the HO2S bank 1 and 2 inputs. This is called closed loop fuel control. During open loop, the VCM ignores the HO2S input and bases fuel delivery upon TP, engine coolant, and MAF sensor input.

MAF--Range (0-512 g/s): The VCM converts the Mass Air Flow sensor signal input from frequency into grams per second. The MAF indicates the amount of air entering the engine.

MAF Frequency--Range (Frequency in Hertz): The MAF produces a frequency as it measures airflow entering the engine. The VCM detects this frequency on the signal circuit and converts it into a grams per second (g/s) of airflow scale. This raw frequency can be displayed by the scan tool as it is detected by the VCM.

Manifold Absolute Pressure (MAP)--Range (10-104 kPa): The Manifold Absolute Pressure (MAP) sensor measures the change in intake manifold pressure caused by engine load and engine speed changes. During WOT, MAP will be maximum. During decel, vacuum will be high in the intake and MAP will be displayed at its minimum pressure.

Manifold Absolute Pressure (MAP)--Range (0.0-5.0 Volts): The MAP sensor produces a low signal voltage when the manifold pressure is low. A low MAP voltage indicates a high vacuum in the intake manifold. The MAP sensor produces a high signal voltage when the manifold pressure is high. A high MAP voltage indicates a low vacuum in the intake manifold. With the ignition ON and the engine OFF, the manifold pressure equals the ambient atmospheric pressure. This will produce a relatively high MAP signal voltage. The VCM uses this information as an indication of the vehicles altitude. This parameter is referred to as the BARO.

Mileage Since DTC Clear--Range (Km/Mi): The scan tool indicates the total distance the vehicle has traveled since the DTCs were cleared.

Misfire Current Cyl. #1-#8 -- Range (Current Counts): The scan tool displays the number of misfires detected during each 200 crankshaft revolution sampling period. Each cylinder has its own register to record misfires that have occurred. If the Misfire Current Cyl is incrementing, it will be reset to zero after 200 crankshaft revolutions. If the misfire DTC has set, the number of misfires in the register will be added to the Misfire History cyl register each time the current cyl. register is reset to zero.

Misfire History Cyl. #1-#8 -- Range (Counts): The scan tool displays a record of misfires that have occurred since the misfire DTC was set. This parameter will be summed with the current cylinder register each time the 200 crankshaft revolution sample is reset to zero if the current misfire test block exceeds an allowable misfire threshold.

PCM/VCM in VTD Fail Enable--(Yes/No): This parameter will indicate when the VCM detects a VTD failure after the vehicle was running. VCM in VTD Fail Enable will indicate YES if this occurs and will allow future operation of the vehicle without shutting OFF fuel when the vehicle is started. Normal conditions with no DTCs set will display this parameter as NO.

Pre HO2S-- (Not Ready/Ready): The scan tool will display Not Ready until the VCM has commanded closed loop. The HO2S is then considered Ready for operation.

Post HO2S-- (Not Ready/Ready): The scan tool will display Not Ready until the VCM has determined that the post HO2S is sufficiently warm for full operation.

Power Enrichment-- (Active/ Inactive): The Power Enrichment parameter indicates if the Power Enrichment mode is active. Power enrichment fueling is entered during high engine load operation to provide for maximum engine output.

Purge Leak Test-- (Pass/Not Run/Fail): The Purge Leak Test parameter indicates if the evaporative system leak test has Passed or Not Run/Failed.

Reference Pulse Occurred-- (Yes/No): The scan tool will indicate a Yes after a CKP sensor reference pulse has been detected by the VCM.

Rich/Lean Bn 1--(Rich/Lean): The Rich/Lean Bn 1 parameter indicates the oxygen content in the exhaust gases in bank 1. Rich indicates low oxygen content, lean indicates high oxygen content.

Rich/Lean Bn 2-- (Rich/Lean): The Rich/Lean Bn 2 parameter indicates the oxygen content in the exhaust gases in bank 2. Rich indicates low oxygen content, lean indicates high oxygen content.

Short Term Fuel Trim (FT) Bn 1--Range (0-255 Counts): The Short Term FT was formerly the fuel integrator. The Short Term FT represents a short term correction to the fuel delivery by the VCM in response to the amount of time the HO2S voltage spends above or below the 450 mV threshold. A HO2S voltage reading below 450 mV indicates a lean air to fuel mixture. If the HO2S voltage averages below the 450 mV threshold, the short term fuel trim counts increase in order to add fuel. If the HO2S voltage averages above the 450 mV threshold, the VCM reduces the fuel delivery in order to compensate for the indicated rich condition.

Short Term Fuel Trim (FT) Bn 1--Range (Percentage of Compensation Required): The Short Term FT was formerly the fuel integrator. The Short Term FT represents a short term correction to the fuel delivery by the VCM in response to the amount of time the HO2S voltage spends above or below the 450 mV threshold. As fuel compensation is required, the difference between commanded Short Term FT and 128 counts will be displayed as a percentage.

Short Term Fuel Trim (FT) Bn 2--Range (0-255 Counts): The Short Term FT was formerly the fuel integrator. The Short Term FT represents a short term correction to the fuel delivery by the VCM in response to the amount of time the HO2S voltage spends above or below the 450 mV threshold. A HO2S voltage reading below 450 mV indicates a lean air to fuel mixture. If the HO2S voltage averages below the 450 mV threshold, the short term fuel trim counts increase in order to add fuel. If the HO2S voltage averages above the 450 mV threshold, the VCM reduces the fuel delivery in order to compensate for the indicated rich condition.

Short Term Fuel Trim (FT) Bn 2--Range (Percentage of Compensation Required): The Short Term FT was formerly the fuel integrator. The Short Term FT represents a short term correction to the fuel delivery by the VCM in response to the amount of time the HO2S voltage spends above or below the 450 mV threshold. As fuel compensation is required, the difference between commanded Short Term FT and 128 counts will be displayed as a percentage.

Small Leak Test--(Pass/Not Run/Fail): The Small Leak Test runs immediately after the Weak Vacuum Test. The EVAP system is closed and the fuel tank vacuum is monitored by the VCM. A slow loss of vacuum rate will cause this test to fail. This test will indicate either Pass or Not Run/Failed.

Spark--Range (-96 to -255 Degrees): The Spark Advance is a display of the spark advance calculation which the VCM is provided to the ignition control module. The VCM calculates the desired spark advance using data such as engine temperature, RPM, load and vehicle speed.

Spark Control-- (Advance/Retard): The Spark Control parameter indicates whether the VCM is advancing or retarding spark.

Start Up ECT--Range (-40 to 215°C (-40 to 419°F)):  The VCM records the engine coolant temperature when the engine is started.

Startup IAT--Range (-40 to 151°C (-40 to 303°F)):  the VCM records the Intake Air temperature when the engine is started.

TCC Enable-- (Yes/No): The scan tool indicates whether or not the VCM commanded the TCC solenoid to an active state.

TCC Duty Cycle--Range (0-100%): The scan tool indicates the duty cycle that the VCM has commanded to control the TCC solenoid. The TCC solenoid is pulse width modulated to provide a determined amount of pressure, which is displayed as a percentage of the supply pressure. This provides for smooth TCC engagement.

TFP Switch A/B/C Range-- (ON/OFF)(ON/OFF)(ON/OFF): The A/B/C Range parameter indicates the current state of the transmission range switch. These are pressure switches internal to the transmission.

Total Misfire Current Count--Range (0-255): The Total Misfire Current Count indicates the total number of cylinder firing events that the VCM detected as being misfires during the last 200 crankshaft revolution sample period. Misfire is diagnosed using crankshaft speed variations in relation with engine speed and load data.

Total Misfire Failures--Range (0-255): The Total Misfire Failures indicates the total number of cylinder firing events that the VCM determined as misfires during the last 200 crankshaft revolution sample.

Total Misfire Passes Since First Failure--Range (0-65,535): The Total Misfire Passes Since First Fail indicates the total number of cylinder firing events that the VCM detected as being good since the misfire DTC was set.

TP Angle--Range (0-100%): The VCM computes the TP angle from the TP signal voltage input. This is an indication of throttle blade angle demanded by the operator. The TP angle should read 0 percent at idle. At 0 percent, the TP voltage will read below 0.90 volts. The TP angle should read 100 percent at wide open throttle.

Throttle Position (TP) Sensor--Range (0-5 Volts): The VCM uses the Throttle Position in order to determine the amount of throttle demanded by the operator of the vehicle. The TP sensor reads between 0.36-0.96 volts at idle to above 4.0 volts at wide open throttle (WOT).

TR Switch--Range (One of the following P R N D4 D3 D2 D1): The Trans Range (TR) Switch indicates the Trans Range selected by the operator.

Valid Ref. Pulse Occurred-- (Yes/No): The scan tool will indicate YES after 2 or more CKP sensor reference pulses have been detected by the VCM.

Vehicle Speed-km/h--Range (0-255): The Vehicle Speed parameter indicates in MPH or km/h how fast the drive wheels are turning.

VTD Auto Learn Timer-- (Active/Inactive): The Auto Learn Timer will indicate if the Vehicle Theft Deterrent (VTD) system is currently in the auto learn Mode. The auto learn mode requires approximately 10 minutes to complete.

VTD Fuel Disable-- (Active/Inactive): If the VCM has not received the correct password from the passlock module or body control module (if equipped), the VCM will disable fuel to the fuel system. If this occurs, the scan tool will display Active.

VTD Fuel Disable Until Ign OFF-- (Yes/No): With the ignition ON and a VTD code stored, the scan tool will display Yes.

Weak Vacuum Test-- (Pass/Not Run/Fail): The Weak Vacuum Test will run only if the Loaded Canister Test does not pass. Insufficient vacuum in the evaporative system will cause this test to fail. The two states of this parameter are Pass and Not Run/Fail.