GM Service Manual Online
For 1990-2009 cars only
3X Crank Sensor: 3 X crank sensor indicates engine RPM based on the 3X reference signal input to the powertrain control module (PCM).

18X Crank Sensor: 18 X crank sensor indicates engine RPM based on the 18 X reference signal input to the PCM.

A/C High Side Pressure Sensor: Scan tool displays 0.00-5.00 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 Off For WOT: Scan tool displays YES or NO. Indicates whether A/C is commanded OFF due to wide open throttle (WOT).

A/C Pressure Disable: Scan tool displays YES or NO. Indicates whether A/C is commanded OFF due to excessive or insufficient pressure.

A/C Relay Command: Scan tool displays On or Off. Indicates intended PCM output to the A/C relay.

A/C Relay Circuit Status: Scan tool displays OK, Fault, or Invalid State. Indicates the diagnostic state of the A/C relay control circuit.

A/C Request Signal: This parameter displays the state of the air conditioning (A/C) request input to the control module from the heating, ventilation, and air conditioning (HVAC) controls. The scan tool will display Yes or No. Yes indicates the control module is receiving a request from the HVAC system to ground the A/C clutch relay control circuit, engaging the A/C compressor clutch. No indicates the control module is not receiving a request from the HVAC system to ground the A/C clutch relay control circuit.

Air Fuel Ratio: Scan tool range 0.0-25.5. 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 (PE) or 3-way catalytic converter (TWC) protection modes. A higher air fuel ratio indicates a leaner commanded mixture. This can be seen during Decel Fuel Mode.

APP Average: This parameter displays the average of the 3 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 counts.

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: This parameter displays the angle of the accelerator pedal position (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 Sensor 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: This parameter displays the angle of the accelerator pedal position (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.

BARO: Scan tool range 10-105 kPa/0.00-5.00 volts. The barometric pressure (BARO) reading is determined from the manifold absolute pressure (MAP) sensor signal monitored during key up and WOT conditions. BARO is used to adjust fuel delivery and spark advance to compensate for altitude changes.

Boost Solenoid Circuit Status: Boost Solenoid Circuit Status indicates the diagnostic state of the output driver for the boost solenoid control circuit. The scan tool displays Fault, OK or Invalid State

Boost Solenoid Command: Boost Solenoid Command indicates the commanded state of the boost solenoid. The scan tool displays percent.

CMP Sensor Signal Present: Camshaft position (CMP) Sensor Signal Present indicates if the PCM is receiving the cam sensor reference signal from the ignition control module (ICM). The scan tool displays Yes or No.

Cruise Control Active: The scan tool displays Yes or No. The PCM determines the current status of cruise control operation. An active cruise control system is displayed as Yes.

Cruise Disengage (1-8) History: The scan tool displays the last reasons why the cruise control system was disengaged. Refer to the Scan Tool Data Definitions (Disengaged History) for description

Cruise ON/OFF Switch: The scan tool displays ON or OFF. The PCM monitors the cruise control set/coast and resume/accelerate switch signal circuit. A closed switch is displayed as ON.

Cruise Resume/Accel. Switch: The scan tool displays ON or OFF. The PCM monitors the cruise control set/coast and resume/accelerate switch signal circuit. A closed switch is displayed as ON. The cruise control ON/OFF switch must be switched ON in order to correctly view the Cruise Resume/Accel. Switch parameter.

Cruise Set/Coast Switch: The scan tool displays ON or OFF. The PCM monitors the cruise control set/coast and resume/accelerate switch signal circuit. A closed switch is displayed as ON. The cruise control ON/OFF switch must be switched ON in order to correctly view the Cruise Set/Coast Switch parameter.

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.

Cycles of Misfire Data: Scan Tool Range--0-99 Counts. Indicates the total number of cylinder firing events that were detected as being misfires during the last 200 crankshaft revolution sample period.

Cyl. 1-6 Injector Circuit History: Scan Tool Displays--Fault or OK This parameter saves the state of the driver circuit for this device.

Cyl. 1-6 Injector Circuit Status: Scan Tool Displays--Fault or OK This parameter indicates the state of the driver circuit for this device.

Decel Fuel Cutoff: 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 40 km/h (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 displays volts or a range from 0-100 percent. Represents the exhaust gas recirculation (EGR) pintle position that the PCM is commanding. Desired EGR Position should stay close to EGR position sensor.

Desired Idle Speed: Scan tool range 0-3187 RPM. Represents the idle speed that is commanded by the PCM. The PCM will compensate for various engine loads based on engine coolant temperature (ECT) to keep the engine at the desired idle speed.

Driver Module 1 Status: Driver Module 1 Status indicates the diagnostic state of the module. The scan tool displays Enabled, Off-High Volts, Off-High Temp, or Invalid State.

Driver Module 2 Status: Driver Module 2 Status indicates the diagnostic state of the module. The scan tool displays Enabled, Off-High Volts, Off-High Temp, or Invalid State.

Driver Module 3 Status: Driver Module 3 Status indicates the diagnostic state of the module. The scan tool displays Enabled, Off-High Volts, Off-High Temp, or Invalid State.

Driver Module 4 Status: Driver Module 4 Status indicates the diagnostic state of the module. The scan tool displays Enabled, Off-High Volts, Off-High Temp, or Invalid State.

EC Ignition Relay Circuit: Indicates the diagnostic state of output driver for the EC ignition relay control circuit. The scan tool displays Fault, OK, Invalid State.

ECT Sensor: Scan tool range -40 to +151°C (-40 to +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, the internal resistance is high, the PCM monitors a high signal voltage and interprets the higher voltage as a cold engine. As the sensor warms, the internal resistance decreases, the voltage signal decreases and the PCM interprets the lower voltage as a warm engine.

EGR Flow Test Count: Scan tool range 0-255. 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 Learned Minimum Position: Scan tool range 0.0-5.0 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, the PCM will illuminate the MIL to indicate an EGR system fault.

EGR Position Sensor: Scan tool range 0.00-5.00 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 Position Sensor: Scan tool range 0-100 percent. Represents the actual position of the EGR pintle in percent. 0 percent displayed indicates a fully extended pintle, the EGR valve is closed.

EGR Position Variance: Scan tool range 0-100 percent. Indicates the difference between Desired EGR Position and Actual EGR Position currently being monitored by the PCM. If the EGR Position Variance reaches an unacceptable level, the PCM will illuminate the MIL to indicate an EGR system fault.

EGR Solenoid Command: Scan tool range 0-100 percent. Represents the EGR valve driver pulse width modulation (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 Solenoid Circuit Status: EGR Solenoid Circuit Status indicates the diagnostic state of the output driver for the EGR solenoid circuit. The scan tool displays Fault, OK or Invalid State.

Engine Load: Scan tool range 0-100 percent. Engine load is calculated by the PCM from engine speed and mass air flow (MAF) sensor readings. Engine load should increase with an increase in RPM or air flow.

Engine Oil Level Switch: Scan tool displays OK or LOW. Indicates the oil level as determined by the engine oil level switch.

Engine Oil Life Remaining: Scan tool range 0-100 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.

Engine Oil Pressure Switch: Engine oil pressure switch indicates the state of the switch. The scan tool displays Low or OK.

Engine Run Time: Scan tool range 00:00:00-99:99:99 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 0-9999 RPM. Engine speed is computed by the PCM from the 3 X reference input. The engine speed should remain close to desired idle under various engine loads with engine idling

EVAP Fault History: Scan Tool displays No Fault, Excess Vacuum, Purge Valve Leak, Small Leak, Weak Vacuum or No Test Result.

EVAP Purge Solenoid Circuit Status: Evaporative emission (EVAP) Purge Solenoid Circuit Status indicates the diagnostic state of the output driver for the EVAP purge solenoid circuit. The scan tool displays Fault, OK or Invalid State.

EVAP Purge Solenoid Command: Scan tool range 0-100 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.

EVAP Vent Solenoid Circuit Status: EVAP Vent Solenoid Circuit Status indicates the diagnostic state of the output driver for the EVAP vent solenoid circuit. The scan tool displays Fault, OK or Invalid State.

EVAP Vent Solenoid Command: The scan tool displays the commanded state of the EVAP vent solenoid as either venting or not venting.

FC Relay 1 Circuit Status: FC Relay 1 Circuit Status indicates the diagnostic state of the output driver for the FC relay 1 circuit. The scan tool displays Fault, OK or Invalid State.

FC Relay 1 Command: FC relay 1 Command indicates the commanded state of the FC relay 1. The scan tool displays ON or OFF.

FC Relay 2 and 3 Circuit Status: FC Relay 2 and 3 Circuit Status indicates the diagnostic state of the output driver for the FC relay 2 and 3 circuits. The scan tool displays Fault, OK or Invalid State.

FC Relay 2 and 3 Command: FC Relay 2 and 3 Command indicates the commanded state of the FC relays 2 and 3. The scan tool displays ON or OFF.

Fuel Pump Relay Circuit Status: Fuel Pump Relay Circuit Status indicates the diagnostic state of the output driver for the fuel pump relay control circuit. The scan tool displays Fault, OK or Invalid State.

Fuel Pump Relay Command: Scan tool displays ON or OFF. Indicates the PCM commanded state of the fuel pump relay control circuit.

Fuel Tank Level Remaining: Fuel Tank Level Remaining indicates the level of fuel remaining in the fuel tank. The scan tool displays percent.

Fuel Tank Pressure Sensor: Scan Tool Displays--0-5 volts, -32.69 to +014.01 mm Hg, or -17.5 to +7.5 in of  H2O Fuel tank pressure (FTP) is used extensively for EVAP purge control and EVAP system diagnostics.

Fuel Trim Cell: Scan tool range 0-9 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 FT is responding to short term fuel trim. If the Fuel Trim Learn displays NO, the long term FT will not respond to changes in short term FT.

Gen L-Terminal Signal Command: Scan tool displays ON or OFF. OFF displayed indicates that the PCM has commanded the generator control circuit OFF.

HO2S 1:  Scan tool range 0-1,132 mV. Represents the fuel control exhaust oxygen sensor (O2S) output voltage. Should fluctuate constantly within a range between 10 mV, lean exhaust, and 1,000 mV, rich exhaust, while operating in Closed Loop.

HO2S 2: Scan tool range 0-1,132 mV. Represents the catalyst monitor exhaust O2S output voltage. If the catalyst is operating efficiently, the heated oxygen sensor (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 1 and 2 Heater Circuit Status: The HO2S Heater Circuit Status indicates the diagnostic state of the output driver for the heater control circuit. The scan tool displays Fault, OK, or Invalid State.

HO2S 1 and 2 Heater Command: The HO2S 1 and 2 Heater Command displays the commanded state of the HO2S heater. The scan tool displays ON or OFF.

HO2S 1 and 2 Heater Current: The HO2S 1 and 2 Heater Current displays the current through the control module when the HO2S Heater is commanded ON. The scan tool displays the current in amperage.

IAT Sensor: Scan tool range -40 to +151°C (-40 to +304°F). The PCM converts the resistance of the intake air temperature (IAT) sensor to degrees. The PCM uses 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 Signal: Scan tool range 0-25.5 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 (ICM) is controlling the spark advance at a fixed 10 degrees before top dead center (BTDC), bypass mode. IC displayed indicates that the PCM has requested control of the spark advance, IC mode. The ICM determines the correct operating mode based on the level of voltage that the PCM applies to the ICM bypass circuit. The PCM provides 5 volts to the ICM 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 ICM does not receive the voltage , the module will control spark timing.

IMS: The Internal Mode Switch (IMS) displays active position of the transmission shift position. The scan tool displays P, R, N, D4, D3, D2, D1.

Initial Brake Apply Signal: The Initial Brake Apply Signal displays the active position of the brake switch. The scan tool displays Applied/Released.

Injector PWM: Injector PWM indicates the commanded PWM of the fuel injectors. The scan tool displays milliseconds.

Knock Retard: Scan tool range 0.0-25.5 degrees. Indicates the amount of spark the PCM is removing from the IC spark advance in response to the signal from the knock sensors (KS). The traction control system Desired Torque signal from the electronic brake and traction control (EBTCM) may cause knock retard to display a value more than 0.0 degrees if traction control is active.

Long Term FT: Scan tool range -23 to +16 percent. Long term FT is derived from the short term FT 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 more 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 FT, a value in the negative range due to canister purge at idle should not be considered unusual. The PCMs maximum authority to control Long term FT allows a range between -23 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 O2S voltage. In Open Loop, the PCM ignores the O2S voltage and bases the amount of fuel to be delivered on TP, ECT, and MAF sensor inputs only.

MAF Sensor: Scan tool range 0.0-512 gm/s. 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: Scan tool range 0-32,000 Hz. The MAF sensor input signal to the PCM is a frequency which varies from around 3,000 Hz at idle to above 7,000 Hz at WOT. The PCM converts this frequency signal to grams per second to be displayed on the scan tool as MAF.

MAP Sensor: Scan tool range 10-105 kPa/0.00- 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 Command: Scan tool displays ON or OFF. Indicates the PCM commanded state of the malfunction indicator lamp (MIL).

MIL Circuit Status: MIL Circuit Status indicates the diagnostic state of the output driver for the MIL circuit. The scan tool displays Fault, OK or Invalid State.

Misfire Current Cyl. 1-6: Scan tool range 0-198 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. 1-6: Scan tool range 0-65535 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.

Number of DTC(s): Scan Tool Displays-- number This parameter displays the quantity of active DTCs.

PCM/VCM in VTD Fail Enable: Scan Tool Displays--ACTIVE or INACTIVE. If applicable. The theft deterrent fuel enable is an input from the vehicle theft deterrent (VTD) system that signals the PCM to enable the injectors and the crank relay if the proper signal is received. The scan tool will normally display INACTIVE. If the VTD system does not send the correct theft deterrent fuel enable signal to the PCM, the display will switch to ACTIVE and the fuel system and starter control may be disabled. Refer to VTD diagnosis for further information.

Power Enrichment: Scan tool displays ACTIVE or INACTIVE. ACTIVE displayed indicates that the PCM has detected conditions appropriate to operate in power enrichment (PE) mode. The PCM will command PE mode when a large increase in TP and load is detected. While in PE, 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 control module receives a signal from the TAC module that a throttle actuator control system fault is occurring. The scan tool displays inactive when the engine is operating normally.

Short Term FT:  Scan tool range -11 to +20 percent. Short term FT represents a short-term correction to fuel delivery by the PCM in response to the amount of time the fuel control O2S voltage spends above or below the 450 mV threshold. If the O2S voltage has mainly remained less than 450 mV, indicating a lean air/fuel mixture, short term FT will increase into the positive range above 0 percent and the PCM will add fuel. If the O2S 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 FT to read in the negative range during normal operation. The PCMs maximum authority to control fuel trim allows a range between -11 to +20 percent. Fuel trim values at maximum authority may indicate an excessively rich or lean system.

Spark: Scan tool range -64 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 ICM sets spark advance at a fixed value of 10 degrees BTDC while operating in bypass mode, the displayed Spark advance only reflects true spark timing when the PCM has commanded IC mode.

Starter Enable Relay Circuit Status: Starter Enable Relay Circuit Status indicates the diagnostic state of the output driver for the starter enable relay control circuit. The scan tool displays Fault, OK or Invalid State.

Starter Relay Command: Scan tool displays ON or OFF. A Disabled display 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.

Start-Up ECT: Scan tool range -40 to +151°C (40 to +304°F). Indicates the ECT 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 to +151°C (-40 to +304°F). Indicates the IAT at the time that the vehicle was started. Used by the HO2S diagnostic to determine if the last startup was a cold start.

Stop Lamp Signal: The Stop Lamp Signal displays the active position of the Stop Lamp Switch. The scan tool displays ON or OFF.

TAC/PCM Communication Signal: This parameter indicates the status of the communication between the TAC module and the control module. The scan tool will display OK if the circuits are operating normally. The scan tool will display Fault if there is an interruption in the communication.

TCC Brake Pedal Switch: Torque control converter (TCC) brake pedal switch indicates the state of the switch. The scan tool displays Applied or Released.

TCC PWM Solenoid Circuit: The TCC PWM Solenoid Circuit indicates the diagnostic state of the output driver for the TCC PWM solenoid control circuit.

TCC PWM Solenoid Command: TCC PWM Solenoid Command indicates the commanded PWM signal to the solenoid. The scan tool displays Hz.

TCS Circuit Status: Traction control system (TCS) Circuit Status indicates the diagnostic state of the output driver for the TCS circuit. The scan tool displays Fault, OK or Invalid State.

TP Desired Angle: This parameter indicates the TP angle commanded by the control module. The scan tool will display a low value at idle, and a high value at wide open throttle (WOT).

TP Indicated Angle: This parameter displays the angel 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 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: This parameter displays the angle of the throttle position (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 throttle position (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: This parameter displays the angle of the throttle position (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: Scan tool range 0.00-5.00 Volts. The voltage being monitored by the PCM on the TP sensor signal circuit.

Traction Control Status (If Equipped):  Scan tool displays ACTIVE or INACTIVE. ACTIVE displayed indicates that the traction control system is taking action to reduce drive wheel slippage.

Torque Request Signal (If Equipped):  Scan tool range 0-100 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 solenoid PWM, or increasing air/fuel ratio. The PCM can also turn OFF up to 3  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.

Torque Delivered Signal (If Equipped): Scan tool range 0-100 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.

Vehicle Speed Sensor:  Scan tool range 0-255 km/h, 0-155 mph. The vehicle speed sensor (VSS) signal is converted into km/h and mph for display.

VTD Auto. Learn Timer: Scan Tool Displays--ACTIVE or INACTIVE. The auto learn timer is the indication if the VTD system is in the learn mode and has not timed out.

VTD Fuel Disable: Scan Tool Displays--ACTIVE or INACTIVE. If applicable. The theft deterrent fuel enable is an input from the VTD system that signals the PCM to enable the injectors and the crank relay if the proper signal is received. The scan tool will normally display INACTIVE. If the VTD system does not send the correct theft deterrent fuel enable signal to the PCM, the display will switch to ACTIVE and the fuel system and starter control may be disabled. Refer to VTD diagnosis for further information.

VTD Fuel Disable Until Ign. OFF: Scan Tool Displays--Yes or NO With the ignition ON and a VTD code present, the scan tool displays Yes.