Part 2

Scan Tool Data Definitions

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 ECM 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.

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

Int. DMP Angle
- This parameter displays the actual intake camshaft position in degrees.

Int. CMP Bank 1 Command
- This parameter displays the intake camshaft position in percent of range as commanded by the control module.

Int. CMP Solenoid Circuit Status
- This parameter displays the state of the intake camshaft actuator solenoid control circuit. The parameter displays Fault if the camshaft actuator solenoid control circuit is open, shorted to ground, or shorted to voltage. The parameter displays Indeterminate until the circuit has been commanded ON. This parameter may not change if the scan too is used to command the CMP solenoid ON.

Int. CMP Variance
- This parameter displays in degrees, the difference between the desired intake camshaft position and the actual intake camshaft position.

Knock Retard
- The scan tool displays �.
Indicates the amount of spark the ECM is removing from ignition control (IC) spark advance in response to the signal from the knock sensors. The traction control system desired torque signal from the electronic brake and traction control module (EBTCM) may cause knock retard to display a value more than 0.0 degrees if traction control is active.

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.

Long Term FT
- The scan tool displays percentage. The ECM derives the long term fuel trim from the short term fuel trim value. The long term fuel trim represents a long term correction of fuel delivery. A value of 0 percent indicates that fuel delivery requires no compensation in order to maintain the ECM commanded air/fuel ratio. A negative value significantly below 0 percent indicates that the fuel system is rich and the ECM is reducing the fuel delivery. A positive value significantly more than 0 percent indicates that a lean condition exists and the ECM compensates by adding fuel. Fuel trim values at maximum authority indicates an excessively rich or lean system.

Long Term 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 this bank of 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 this bank of the engine. A value of 0 percent indicates no compensation is required to operate the engine at the desired air/fuel ratio.

Loop Status
- Closed loop indicates that the ECM is controlling fuel delivery according to oxygen sensor voltage. In open loop, the ECM ignores the oxygen sensor voltage and bases the amount of fuel to be delivered on throttle position (TP) sensor, ECT, and mass air flow (MAF) sensor inputs only.

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 in. The scan tool will display a high value for a large amount of long term fuel correction, and 0 percent 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 Sensor
- The scan tool displays g/s
The scan tool displays a range of 0.0-655 g/s. The 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 ECM 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.

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.

MAP 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 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 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 10-104 kPa. The MAP sensor measures the absolute pressure in the intake manifold.

MAP Sensor
- The scan tool displays Volts
The 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 0-5 volts. The MAP sensor measures the absolute pressure in the intake manifold.

MIL Circuit Status
- This parameter displays the status of the output driver for the malfunction indicator lamp (MIL) 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.

MIL Command
- This parameter displays the commanded state of the 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 indicates the reason the control module illuminated the MIL. The scan tool will display YES when the MIL is requested as a result of an A or B type DTC. The scan tool will display NO if the MIL is illuminated for another reason, such as transmission DTCs.

Misfire Current Cyl. 1-4
- 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. 1-4
- 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.

PNP Switch
- This parameter displays whether the transmission range selector is in Park or Neutral.

Power Enrichment
- Scan tool displays ACTIVE or INACTIVE. ACTIVE displayed indicates that the ECM has detected conditions appropriate to operate in Power Enrichment mode. The ECM will command Power Enrichment mode when a large increase in throttle position and load is detected. While in Power Enrichment, the ECM 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 ECM receives a signal from the TAC module that a throttle actuator control system fault is occurring. The ECM limits the engine power.

Short Term FT
- The scan tool displays percentage. The short term fuel trim represents a short term correction to fuel delivery by the ECM 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 mainly remains less than 450 mV, indicating a lean air/fuel mixture, short term fuel trim increases into the positive range above 0 percent. The ECM adds fuel. If the oxygen sensor voltage stays mainly above the threshold, the short term fuel trim decreases below 0 percent into the negative range. The ECM reduces the fuel delivery in order to compensate for the indicated rich condition. Under certain conditions such as an extended idle and a high ambient temperature, the canister purge may cause the short term fuel trim to read in the negative range during normal operation. The fuel trim values at maximum authority may indicate an excessively rich or lean system.

Short Term FT Test Avg.
- The scan tool displays %. This parameter indicates the average short term fuel trim for this bank. The scan tool will display a value more than 0 if the time is being added to the injector pulse width, increasing the amount of fuel to that bank of the engine to compensate for a lean condition sensed by the oxygen sensors on that bank. The scan tool will display a value less than 0 if time is being subtracted from the injector pulse width, reducing the amount of fuel to the engine to compensate for a rich condition sensed by the oxygen sensors on that bank. A value of 0 percent indicates no compensation is required to operate the engine at the desired air/fuel ratio.

Spark
- The scan tool displays a range of -64 to +64°. The scan tool displays the amount of degrees the ECM commands. The ECM computes the desired spark advance using the following: (1) ECT, (2) engine speed (RPM), (3) load, (4) vehicle speed. The ECM 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.

Start Up ECT
- Indicates the engine coolant temperature at engine start up.
The scan tool displays a range of -40 to +150°C (-40 to +302°F). The scan tool displays the engine ECT at the time the engine was started. The ECM uses start-up ECT for certain DTCs.

Start Up IAT
- Indicates the IAT at the time that the vehicle was started.
The scan tool range is -40 to +150°C (-40 to +302°F). This parameter indicates the ambient air temperature at start-up.

TCC/Cruise Brake Pedal Switch
- This parameter displays the position of the torque converter clutch (TCC) brake pedal switch input to the control module. The scan tool displays Applied, Released, or Invalid.

TCS Torque Delivered Signal
- Represents the pulse width modulation (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 ECM is responding properly to the traction control desired torque signal.

TCS Torque Signal
- Represents the PWM signal from the EBTCM. The EBTCM reduces the traction control desired torque signal pulse width when a drive wheel slippage situation is detected. The ECM monitors the traction control desired torque signal and reduces drive wheel slippage as necessary by retarding spark timing.

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 Count
- 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 Sensor 1 Learned Minimum
- This parameter displays the learned minimum value of TP sensor 1 as recorded by the control module on start-up for the ignition cycle.

TP Sensor 2 Learned Minimum
- This parameter displays the learned minimum value of TP sensor 2 as recorded by the control module on start-up for the ignition cycle.

TP Desired Angle
- The scan tool displays %. The scan tool displays 0-100 percent. The ECM 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 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 plate is closed. The scan tool will display a high percentage when the throttle plate is 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 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 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 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 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.

Vehicle Speed Sensor
- This parameter indicates the vehicle speed as calculated by the control module based on a signal from the vehicle speed sensor (VSS). The scan tool will display a higher value at higher vehicle speeds, and a lower value at lower vehicle speeds.

Warm-ups w/o Emission Faults
- 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 ECM 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 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 ECM 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 percent.