A/C High Side Pressure: Scan Tool Displays 0.00 to 5.00 Volts. Represents the A/C refrigerant
pressure sensor signal. The amount of pressure indicates the amount of load
that the A/C compressor is placing on the engine. The PCM uses this information
to adjust idle and to control the cooling fans.
A/C Pressure Out Of Range: Scan Tool Displays YES or NO. YES displayed indicated that the
PCM is monitoring an A/C Refrigerant Pressure signal voltage which is too
high or too low to allow the A/C compressor clutch to engage.
A/C Request: Scan Tool Displays YES or NO. Indicates the state of the A/C request
input circuit from the HVAC controls. The PCM uses the A/C request signal
to determine whether A/C compressor operation is being requested.
Actual EGR Position: Scan Tool Range 0 percent to 100 percent. Represents
the actual position of the EGR pintle in percent. 0 percent displayed
indicates a fully extended pintle (EGR valve closed).
Air Fuel Ratio: Scan Tool Range 0.0 to 25.5. Air Fuel Ratio indicates the PCM commanded
value. In closed loop, Air Fuel Ratio should normally be around 14.2 - 14.7.
A lower Air Fuel Ratio indicates a richer commanded mixture, which may
be seen during Power Enrichment or TWC Protection modes. A higher Air Fuel
Ratio indicates a leaner commanded mixture. This can be seen during Decel
Fuel Mode.
BARO: Scan Tool Range 10 to 105 kPa / 0.00 to 5.00 Volts.
The barometric pressure reading is determined from the MAP sensor signal monitored
during key up and Wide-Open Throttle (WOT) conditions. Barometric pressure
is used to adjust fuel delivery and spark advance to compensate for altitude
changes.
Boost Solenoid PWM: Scan Tool Range 0 percent to 100 percent. Represents
the amount of manifold boost pressure commanded by the PCM. 100 percent
displayed indicates full boost commanded.
Commanded A/C: Scan Tool Displays ON or OFF. Represents the PCM commanded state
of the A/C compressor clutch relay driver circuit. The A/C compressor clutch
should be engaged when Commanded A/C displays ON.
Commanded Fan 1 / Commanded Fan 2: Scan Tool Displays ON or OFF. Represents the PCM commanded state
of the fan 1 (low speed) and fan 2 (high speed) control circuits.
Commanded Gen: Scan Tool Displays ON or OFF. OFF displayed indicates that the
PCM has commanded the generator control circuit OFF.
Commanded Starter: Scan Tool Displays ENABLED or DISABLED. Disabled displayed indicates
that the PCM has inhibited starter relay operation. The PCM will inhibit starter
relay operation if the engine is running, a correct VTD password has not
been received from the VTD module or if the starter is engaged for an extended
period of time.
Cruise: Scan Tool Displays ENGAGED or DISENGAGED. Represents the state
of the Cruise Status Input form the SMCC module. Cruise should not display
ENGAGED unless the vehicle is operating in cruise control.
Cruise Inhibited: Scan Tool Displays YES or NO. YES displayed indicates that the
PCM is commanding the SMCC module to inhibit cruise control operation. Should
display YES with park, neutral, reverse or low gear selected.
Current Gear: Scan Tool Displays numbers 1, 2, 3, or 4. The PCM looks at Trans
Range position and the gear commanded by the PCM. The actual forward gear
that the Transaxle is in will be the lower of the two because the manual
valve can override the PCM commanded gear.
Decel Fuel Mode: Scan Tool Displays ACTIVE or INACTIVE. ACTIVE displayed indicates
that the PCM has detected conditions appropriate to operate in Deceleration
Fuel Mode. The PCM will command deceleration fuel mode when a sudden decrease
in throttle position has been detected while the vehicle is traveling over
25 mph. While in Deceleration Fuel mode, the PCM will decrease the amount
of fuel delivered by entering Open Loop and decreasing the injector pulse
width.
Desired EGR Position: Scan Tool Range 0 percent to 100 percent. Represents
the EGR pintle position that the PCM is commanding. Desired EGR Position should
stay close to Actual EGR Position.
Desired Idle Speed: Scan Tool Range 0 to 3187 RPM. Represents the idle speed
that is commanded by the PCM. The PCM will compensate for various engine loads
based on engine coolant temperature to keep the engine at the desired idle
speed.
ECT: Scan Tool Range -40°C (-40°F) to 151°C (304°F).
The Engine Coolant Temperature (ECT) sensor is mounted in the coolant stream.
The PCM applies 5 volts to the ECT sensor circuit. The sensor is
a thermistor which changes internal resistance as temperature changes.
When the sensor is cold (internal resistance high), the PCM monitors a
high signal voltage and interprets it as a cold engine. As the sensor warms
(internal resistance decreases), the voltage signal decreases and the PCM
interprets the lower voltage as a warm engine.
EGR Closed Valve Pintle Position: Scan Tool Range 0.0 to 5.0 Volts. 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 Desired EGR Position is
0 percent and a difference of more than 0.4 volt between
EGR Feedback and EGR Closed Valve Pintle Position is detected, DTC P1406
will set.
EGR Duty Cycle: Scan Tool Range 0 percent to 100 percent. Represents
the EGR valve driver PWM signal from the PCM. A duty cycle of 0 percent
indicates that no EGR flow is being commanded; a 100 percent duty
cycle indicates maximum EGR flow commanded.
EGR Feedback: Scan Tool Range 0.00 to 5.00 Volts. Indicates the EGR pintle
position sensor signal voltage being monitored by the PCM. A low voltage indicates
a fully extended pintle (closed valve); a voltage near 5 volts indicates
a fully retracted pintle (open valve)
EGR Flow Test Count: Scan Tool Range 0 to 255. Indicates the number of EGR flow test
samples collected during the current ignition cycle. The maximum number of
samples allowed is 1 during normal operation. If the PCM battery feed has
been disconnected or a DTC P0401 has been cleared, several EGR flow test
samples will be allowed during the next ignition cycle. This is to allow
repair verification during a single ignition cycle.
EGR Position Error: Scan Tool Range 0 percent to 100 percent. Indicates
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, DTC P1406 will set.
Engine Load: Scan Tool Range 0 percent to 100 percent. Engine
load is calculated by the PCM from engine speed and MAF sensor readings. Engine
Load should increase with an increase in RPM or air flow.
Engine Oil Level: Scan Tool Displays OK or LOW. Indicates the oil level as determined
by the Engine Oil Level switch.
Engine Oil Life: Scan Tool Range 0 percent to 100 percent. Indicates
the engine oil life index. The PCM calculates Engine Oil Life based upon the
number of engine revolutions seen and operating conditions such as calculated
oil temperature. Pressing the Oil Life Monitor reset switch will return
the displayed Engine Oil Life to 100 percent.
EOP Sensor: Scan Tool Range 0.00 to 5.00 Volts. Represents the engine oil pressure
sensor signal voltage. The PCM transmits engine oil pressure information to
the IPC via class 2 serial data. The normal range of the engine oil pressure
sensor is between 0.5 volt at 0 kPa (0 PSI) and 4.5 volts at 883 kPa (128
PSI).
Engine Run Time: Scan Tool Range 00:00:00 to 99:99:99 Hrs:Min:Sec. Indicates the
time elapsed since the engine was started. If the engine is stopped, ENGINE
RUN TIME will be reset to 00:00:00.
Engine Speed: Scan Tool Range 0 to 9999 RPM. Engine speed is computed by the
PCM from the 3X reference input. It should remain close to desired idle under
various engine loads with engine idling
EVAP Canister Purge: Scan Tool Range 0 percent to 100 percent. Represents
the PCM commanded PWM duty cycle of the EVAP Purge valve. 0 percent
displayed indicates no purge; 100 percent displayed indicates full
purge.
Fuel Pump: Scan Tool Displays ON or OFF. Indicates the PCM commanded state
of the fuel pump relay control circuit.
Fuel Pump Speed: Scan Tool Displays NORMAL or HIGH. Indicates the PCM commanded
state of the fuel pump speed control PWM circuit to the fuel pump control
module. The fuel pump will be run at high speed to deliver more fuel volume
when the MAP sensor indicates high engine load or when system voltage is
less than 10 volts.
Fuel Trim Cell: Scan Tool Range 0 to 9 Fuel trim cell is dependent upon engine
speed and MAF sensor readings. A plot of RPM vs. MAF is divided into 10 cells.
Fuel trim cell indicates which cell is currently active.
Fuel Trim Learn: Scan Tool Displays NO or YES. When conditions are appropriate for
enabling long term fuel trim corrections, FUEL TRIM LEARN will display yes.
This indicates that the long term fuel trim is responding to short term
fuel trim. If the Fuel Trim Learn displays NO, long term fuel trim will
not respond to changes in short term fuel trim.
Generator PWM: Scan Tool Range 0 percent to 100 percent. Represents
the field terminal input from the generator. The field PWM duty cycle indicates
generator output level; a higher duty cycle indicates a higher generator
output. The PCM uses the generator F terminal signal to adjust spark and
IAC to compensate for variances in engine load caused by the generator.
HO2S Sen. 1: Scan Tool Range 0 to 1132 mV. Represents the fuel control exhaust
oxygen sensor output voltage. Should fluctuate constantly within a range between
10 mV (lean exhaust) and 1000 mV (rich exhaust) while operating
in Closed Loop.
HO2S Sen. 1: Scan Tool Displays NOT READY or READY. Indicates the status of
the fuel control exhaust oxygen sensor. The scan tool will indicate that the
exhaust oxygen sensors are ready when the PCM detects a fluctuating HO2S
voltage sufficient to allow closed loop operation. This will not occur
unless the exhaust oxygen sensors are warmed up.
HO2S Sen. 2: Scan Tool Range 0 to 1132 mV. Represents the catalyst monitor exhaust
oxygen sensor output voltage. If the catalyst is operating efficiently, the
HO2S 1 signal will be far more active than that produced by the HO2S 2
sensor. If the PCM detects a level of HO2S 2 activity that indicates the
catalyst is no longer operating efficiently, DTC P0420 will be set.
HO2S Warm-Up Sensor 1 / HO2S Warm-Up Sensor 2: Scan Tool Range 00:00 to 99:99 MIN:SEC. Indicates time to warm-up
for each HO2S. The HO2S warm up time is used for the HO2S heater test. The
PCM will run the heater test only after a cold start (determined by engine
coolant and intake air temperature at the time of startup) and only once
during an ignition cycle. When the engine is started the PCM will monitor
the HO2S voltage. When the HO2S voltage indicates a sufficiently active
sensor, the PCM looks at how much time has elapsed since startup. If the
PCM determines that too much time was required for the HO2S to become active,
a DTC will set. If the engine was warm when started, HO2S Warm-Up will
display the value that was stored last time the test ran. If info has been
cleared, HO2S Warm-Up will display 00:00.
HO2S XCounts: Scan Tool Range 0 to 255. Indicates the number of times the HO2S
1 signal has crossed the 450 mV bias voltage during a 1 second interval. A
HO2S 1 signal that almost never crosses the bias voltage could indicate
a fuel trim problem, a faulty HO2S 1 circuit, or a faulty HO2S 1.
IAC Position: Range 0 to 255. Displays the commanded position of the idle air
control pintle in counts. A larger number of counts means that more air is
being commanded through the idle air passage. IAC Position should respond
fairly quickly to changes in engine load to maintain desired idle RPM.
IAT: Scan Tool Range -40°C (-40°F) to 151°C (304°F).
The PCM converts the resistance of the intake air temperature sensor to degrees.
The PCM uses Intake Air Temperature (IAT) to adjust fuel delivery and spark
timing according to incoming air density. IAT is also compared to ECT at
startup to identify cold starts for the HO2S heater and the EVAP diagnostics.
Ignition 1: Scan Tool Range 0 to 25.5 Volts. Represents the system voltage
measured by the PCM at its ignition feed.
Ignition Mode: Scan Tool Displays BYPASS or IC. Indicates the commanded state
of the Bypass signal output from the PCM. When BYPASS is displayed, the ignition
control module is controlling the spark advance at a fixed 10° BTDC
(Bypass mode). IC displayed indicates that the PCM has requested control
of the spark advance (IC mode). The ignition control module determines
the correct operating mode based on the level of voltage that the PCM applies
to the ignition control module bypass circuit. The PCM provides 5 volts
to the ignition control module bypass circuit when conditions are appropriate
for PCM control of spark timing (IC mode). If the PCM does not apply 5
volts to the bypass circuit, or if the ignition control module does not
receive it, the module will control spark timing.
Injector Pulse Width: Scan Tool Range 1 to 1000 msec. The Injector Pulse Width
display Indicates the amount of time the PCM is commanding each injector ON
during each time engine cycle. A longer injector pulse width will cause
more fuel to be delivered. Injector Pulse Width should increase with increased
engine load.
Knock Retard: Scan Tool Range 0.0 degrees to 25.5 degrees. Indicates
the amount of spark the PCM is removing from the 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
greater than 0.0 degrees if Traction Control is active.
Long Term Fuel Trim: Scan Tool Range -23 percent to 16 percent. Long Term
Fuel Trim is derived from the Short Term Fuel Trim value and represents a
long-term correction of fuel delivery. A value of 0 percent indicates
that fuel delivery requires no compensation to maintain the PCM commanded
air/fuel ratio. A negative value significantly below 0 percent indicates
that the fuel system is rich and fuel delivery is being reduced (decreased
injector pulse width). A positive value significantly greater than 0 percent
indicates that a lean condition exists and the PCM is compensating by adding
fuel (increased injector pulse width). Because Long Term Fuel Trim tends
to follow Short Term Fuel Trim; a value in the negative range due to canister
purge at idle should not be considered unusual. The PCM's maximum authority
to control long term fuel trim allows a range between -23 percent
and +16 percent. Fuel trim values at or near maximum authority may
indicate an excessively rich or lean system.
Loop Status: Scan Tool Displays OPEN or CLOSED. 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 TP sensor, engine coolant, and MAF sensor inputs
only.
MAF: Scan Tool Range 0.0-512 gm/s. MAF (Mass Air Flow) is the MAF Input
Frequency converted to grams of air per second. This indicates the amount
of air entering the engine.
MAF Input Frequency: Scan Tool Range 0 to 32000 Hz. The Mass Air Flow sensor
input signal to the PCM is a frequency which varies from around 3000 Hz
at idle to above 7000 Hz at wide-open throttle. The PCM converts
this frequency signal to grams per second to be displayed on the scan tool
as MAF.
MAP: Scan Tool Range 10-105 kPa/0.00 to 4.97 Volts. The
Manifold Absolute Pressure (MAP) sensor measures the change in the intake
manifold pressure from engine load, EGR flow, and speed changes. As intake
manifold pressure increases, intake vacuum decreases resulting in a higher
MAP sensor voltage and kPa reading. The MAP sensor signal is used to monitor
intake manifold pressure changes during the EGR flow test, to update the
BARO reading, and as an enabling factor for many of the diagnostics.
MIL: Scan Tool Displays ON or OFF. Indicates the PCM commanded state
of the Malfunction Indicator Lamp.
Misfire Current Cyl #1- Misfire Current Cyl #6: Scan Tool Range 0 to 198 Counts. The Misfire Current counters indicate
the number of cylinder firing events detected as possible misfires on each
cylinder during the last 200 crankshaft revolutions. The number that the
counters display are twice the actual number of misfire events detected.
The counters may normally display some activity, but the activity should
be very low and nearly equal for all the cylinders.
Misfire History Cyl #1- Cyl #6: Scan Tool Range 0 to 65535 Counts. The Misfire History counters
indicate the total level of misfire that has been detected on each cylinder.
The number that the counters display are twice the actual number of misfire
events detected. The Misfire History counters will not update or show any
activity until a misfire DTC (P0300) has become active. The Misfire History
counters will be updated every time a 200 crankshaft revolution misfire
test failure is detected.
Misfiring Cylinder (Primary) / Misfiring Cylinder (Secondary): Scan Tool Displays 0 or Cylinder #. If a misfire is being detected,
Misfiring Cylinder displays the misfiring cylinder numbers.
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.
Rich/Lean: Scan Tool Displays RICH or LEAN. Indicates whether oxygen sensor
voltage is greater than a 600 mV threshold voltage (rich) or less than a 300
mV threshold voltage (lean). Should change constantly while in closed loop,
indicating that the PCM is controlling the air/fuel mixture properly.
Short Term Fuel Trim: Scan Tool Range -11 percent to 20 percent. Short
Term Fuel Trim represents a short-term correction to fuel delivery by the
PCM in response to the amount of time the fuel control oxygen sensor voltage
spends above or below the 450 mV threshold. If the oxygen sensor voltage
has mainly remained less than 450 mV, indicating a lean air/fuel mixture,
short term fuel trim will increase into the positive range above 0 percent
and the PCM will add fuel. If the oxygen sensor voltage stays mainly above
the threshold, short term fuel trim will decrease below 0 percent
into the negative range while the PCM reduces fuel delivery to compensate
for the indicated rich condition. Under certain conditions such as extended
idle and high ambient temperatures, canister purge may cause Short Term
Fuel Trim to read in the negative range during normal operation. The PCM's
maximum authority to control fuel trim allows a range between -11 percent
and +20 percent. Fuel trim values at maximum authority may indicate
an excessively rich or lean system.
Spark: Scan Tool Range -64 degrees to 64 degrees. Displays the spark timing
being commanded by the PCM on the IC circuit. 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. Because
the ignition control module sets spark advance at a fixed value of 10°
BTDC while operating in Bypass mode, the displayed Spark advance only reflects
true spark timing when the PCM has commanded IC mode.
Start-Up Ect: Scan Tool Range -40°C (-40°F) to 151°C (304°F).
Indicates the Engine Coolant Temperature at the time that the vehicle was
started. Used by the HO2S diagnostic to determine if the last startup was
a cold start.
Start-Up IAT: Scan Tool Range -40°C (-40°F) to 151°C (304°F).
Indicates the Intake Air Temperature at the time that the vehicle was started.
Used by the HO2S diagnostic to determine if the last startup was a cold
start.
Throttle At Idle: Scan Tool Displays YES or NO. Indicates whether the TP Angle being
monitored by the PCM is at 0 percent.
Total Misfire Current Count:: Scan Tool Range 0 to 99. Indicates the total number of cylinder
firing events that were detected as being misfires during the last 200 crankshaft
revolution sample period.
Total Misfire Failures Since First Fail: Scan Tool Range 0 to 65535 Counts. Indicates the number of 200
crankshaft revolution sample periods during which the level of misfire was
sufficiently high to report a failure.
Total Misfire Passes Since First Fail: Scan Tool Range 0 to 65535 Counts. Indicates the number of 200
crankshaft revolution sample periods during which the level of misfire was
sufficiently low to report a pass.
TP Angle: Scan Tool Range 0 percent to 100 percent. TP Angle
is computed by the PCM from the TP Sensor voltage. TP Angle should display
0 percent at idle and 100 percent at wide open throttle.
TP Sensor: Scan Tool Range 0.00 to 5.00 Volts. The voltage being monitored
by the PCM on the TP sensor signal circuit.
Traction Control: Scan Tool Displays ACTIVE or INACTIVE. ACTIVE displayed indicates
that the traction control system is taking action to reduce drive wheel slippage.
Traction Control Desired Torque: Scan Tool Range 0 percent to 100 percent. Represents
the PWM signal from the Electronic Brake and Traction Control Module. The
EBTCM reduces the Traction Control Desired Torque signal pulse width when
a drive wheel slippage situation is detected. The PCM monitors the Traction
Control Desired Torque signal and reduces drive wheel slippage as necessary
by retarding spark timing, decreasing boost sol. PWM, or increasing air/fuel
ratio. The PCM can also turn OFF up to three fuel injectors if the Traction
Control Desired Torque signal indicates a large enough amount of drive
wheel slippage. A problem with the Traction Control Desired Torque signal
should cause DTC P1571 to set.
Traction Control Torque: Scan Tool Range 0 percent to 100 percent. Represents
the PWM signal which indicates the percent of available torque the engine
is delivering to the drive wheels. The EBTCM monitors the Traction Control
Torque signal to ensure that the PCM is responding properly to the Traction
Control Desired Torque signal.
Transmission Range: Scan Tool Displays INVALID, PARK/NEUTRAL, REVERSE, DRIVE 4, DRIVE
3, DRIVE 2, or LOW. Transmission Range represents the decoded status of the
four inputs from the Transaxle Range Switch Assembly. The combination of
transaxle range inputs indicates the position of the transaxle manual valve.
TR Switch P / A / B / C: Scan Tool Displays HIGH or LOW. The TR Switch P / A / B / C display
represents the states of the four inputs from the transaxle range switch.
HIGH displayed indicates a B+ voltage signal being monitored at the PCM,
LOW displayed indicates a grounded input signal. The combination of transaxle
range inputs indicates the position of the transaxle manual valve.
TWC Diagnostic: Scan Tool Displays ENABLED or DISABLED. ENABLED displayed indicates
that MAF, HO2S, ECT, or VSS DTCs that would disable the TWC diagnostic are
not present.
TWC Monitor Test Counter: Scan Tool Range 0-49. The TWC monitor test counter increments
while the TWC system diagnostic test is running and taking samples. When the
TWC Monitor Test Counter reaches 49, the PCM will update the TWC diagnostic
statistical filter. At this point, the TWC Monitor Test Counter will reset
to 0 and begin incrementing again. The TWC Monitor Test Counter is most
useful when verifying a Three-way catalytic converter replacement or any
repair associated with the DTC P0420 diagnostic table.
TWC Protection: Scan Tool Displays ACTIVE or INACTIVE. ACTIVE displayed indicates
that the PCM has detected conditions appropriate to operate in TWC Protection
mode. This is determined based on Engine Load and Engine Coolant Temperature.
While in TWC Protection, the PCM will decrease Air/Fuel Ratio to a value
that depends on Mass Air Flow (higher Mass Airflow = lower Air/Fuel Ratio).
Vehicle Speed: Scan Tool Range 0-255 km/h, 0-155 mph. The vehicle speed
sensor signal is converted into mph and km/h for display.