GM Service Manual Online
For 1990-2009 cars only
8-Digit GM Part Number: The scan tool displays the part number of the control module.

ABS Lamp: The scan tool displays On or Off. This is the state of the ABS indicator as commanded by the IPC.

Air Bag Lamp: The scan tool displays On or Off. The state of the air bag indicator as commanded by the IPC.

Balance: The scan tool displays 0-100%. The amount of left to right balance selected.

Battery : The scan tool displays On or Off. This is the state of the charge indicator as commanded by the IPC.

Battery 1 Low Current: The scan tool displays 0-18 volts. The voltage measured at the battery positive voltage circuit of the driver/passenger door module.

Battery 2 High Current: The scan tool displays 0-18 volts. The voltage measured at the battery positive voltage circuit of the driver/passenger door module.

Battery Voltage: The scan tool displays 0-18 volts. This is the voltage at the battery positive voltage circuit of the BCM.

Battery Voltage: The scan tool displays 0-18 volts. The battery voltage as monitored by the IPC.

Brake Assist: The scan tool displays Active or Inactive. This is the state of the brake assist as monitored by the IPC.

Brake Lamp: The scan tool displays On or Off. This is the state of the BRAKE indicator as commanded by the IPC.

Cargo Door Ajar Switch: The scan tool displays Open or Closed. The BCM monitors the signal circuit of the cargo door ajar switch. An open switch is displayed as Open with the door open.

Cargo Lamp On: The scan tool displays On or Off. This is the state of the cargo lamp as commanded by the IPC.

Cargo Lamp Switch: The scan tool displays On or Off. The scan tool displays On when the cargo lamps are requested from the switch.

Chime: The scan tool displays the commanded state of the audible chime. The scan tool displays NONE when no audible chime is commanded. The scan tool displays HEAD LAMP, KEY IN IGNITION, SEAT BELT, TURN SIGNAL and PARK BRAKE as commanded.

Chime Duration: The scan tool displays the chime rate in cycles corresponding to whether the chime is a fast, medium, or slow rate chime.

Chime Frequency: The scan tool displays the frequency of the chime in Hertz.

Chime Type: The scan tool displays Fast/Medium/Slow. The selected chime rate is displayed

Chime Type: The scan tool displays the commanded state of the audible chime. The scan tool displays NONE when no audible chime is commanded. The scan tool displays HEAD LAMP, KEY IN IGNITION, SEAT BELT, TURN SIGNAL and PARK BRAKE as commanded.

Chime Volume: The scan tool displays 0-100%. The chime volume selected.

Coolant Level Switch: The scan tool displays OK or Low. The PCM monitors the coolant level switch signal circuit and a closed switch is displayed as OK.

Courtesy Lamp Switch:  The scan tool displays Active or Inactive. The BCM monitors the signal circuit of the courtesy lamp switch. A closed switch is displayed as Active.

Cruise Control: The scan tool displays On or Off. The state of the cruise control indicator as commanded by the IPC.

DIC Fuel Info: The scan tool displays On or Off. The IPC monitors the Fuel button of the DIC switch. A closed switch is displayed as On.

DIC Personalization: The scan tool displays On or Off. The IPC monitors the personalization button of the DIC switch. A closed switch is displayed as On.

DIC Select: The scan tool displays On or Off. The IPC monitors the Select button of the DIC switch. A closed switch is displayed as On.

DIC Trip Info: The scan tool displays On or Off. The IPC monitors the Trip button of the DIC switch. A closed switch is displayed as On.

Display Dimming: The scan tool displays Active or Inactive. The IPC monitors the display dimming signal circuit. When the panel dimmer switch is turned Off the signal is displayed as Inactive.

Display Units: The scan tool displays what units is being displayed on the DIC, English or Metric.

Displayed Coolant Temp: The scan tool displays 32-127°C (89-260°F). This is the displayed coolant temperature gage data. This data may differ from the monitored coolant temperature from the PCM.

Displayed Fuel Level: The scan tool displays 0- 100%. This is the displayed fuel gage data. The data may differ from the monitored fuel level in the PCM.

Displayed Odometer: The scan tool displays 0- 999999 km (miles). The scan tool displays the data on the odometer in the IPC.

Displayed Oil Pressure: The scan tool displays 0-682 kPa (0-99 psi). The displayed oil pressure gage value in the IPC.

Displayed Trans Oil Temp: The scan tool displays 29-157°C (84-315°F). This is the displayed transmission oil gage data. The data may differ from the monitored trans oil temperature from the PCM.

Displayed Trip Odometer: The scan tool displays 9999.9 km (miles). The scan tool displays the data on the trip odometer in the IPC.

Door Ajar Switch: The scan tool displays On or Off. The DDM/PDM monitors the signal circuit of the door ajar switch. An open switch is displayed as On with the door open.

Driver Door Ajar Switch: The scan tool displays On or Off. The BCM monitors the signal circuit of the driver door ajar switch. An open switch is displayed as On with the door open.

ECT Sensor: The scan tool displays -39 to +140°C (-38 to +284°F). This is the engine coolant temperature as monitored by the PCM. The voltage is inversely proportional to the engine coolant temperature.

Engine Oil Level Switch: The scan tool displays OK or Low. This is the state of the engine oil level switch as monitored by the PCM. A closed switch is displayed as OK.

Engine Oil Life Remaining: The scan tool displays 0 to 100 percent. This is the engine oil life index that is calculated and maintained by the PCM.

Engine Oil Pressure Sensor: The scan tool displays 0 to 5 volts. The PCM monitors the engine oil pressure sensor signal circuit where a low voltage indicates low pressure.

Engine Speed: The scan tool displays 0-9999 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 the engine idling.

Engine Speed: The scan tool displays 0-9999 RPM. The IPC receives the engine speed from the PCM via the engine speed signal circuit.

Fade: The scan tool displays 0-252 counts. The amount of front to rear fade selected.

Fasten Seat Belt: The scan tool displays On or Off. This is the state of the fasten safety belt indicator as commanded by the IPC.

Fuel Capacity: The scan tool displays Gallons. The DIC receives a class 2 message from the PCM indicating the fuel capacity.

Fuel Level Sensor: The scan tool displays 0 to 5 volts. The PCM monitors the fuel level sensor signal circuit where 0 V is an empty tank.

Fuel Level Sensor Rear Tank (If Equipped): The scan tool displays 0 to 5 volts. The PCM monitors the rear tank fuel level sensor signal circuit where 0 V is an empty tank.

Fuel Tank Level Remaining: The scan tool displays gallons (liters). This is the amount of fuel remaining in the fuel tank as determined by the PCM.

Fuel Tank Level Remaining: The scan tool displays 0 to 100%. The scan tool displays in percentage the amount of fuel remaining in the fuel tank as determined by the PCM.

Fuel Tank Rated Capacity: The scan tool displays gallons (liters). This is the fuel tank rated capacity as determined by the PCM.

Hazard Switch Signal: The scan tool displays On or Off. The BCM monitors the hazard switch signal circuit . When the hazard switch is turned Off the signal is displayed as Off.

Headlamp Relay Feedback: The scan tool displays On or Off. This is the state of the headlamp and the panel dimmer switch. The scan tool displays On when the headlamp and the panel dimmer switch is turned On or in auto position with the ambient light sensor in its dark state.

Headlamp Switch:  The scan tool displays Active or Inactive. The BCM monitors the signal circuit of the headlamp switch. A closed switch is displayed as Active.

Headlamps On Indicator: The scan tool displays Off or On. Indicates if the headlamps on indicator is currently On.

High Beam Lamp: The scan tool displays On or Off. This is the state of the high beam indicator as commanded by the IPC.

High Beam Relay: The scan tool displays the commanded state of the high beam relay. The scan tool displays On when the BCM allows the high beam relay to go to ground to activate the high beam lamps.

High Beam Switch: The scan tool displays On or Off. This is the position of the high beam switch where an active switch is displayed as On.

Hood Ajar Switch: The scan tool displays Active or Inactive. The BCM monitors the signal circuit of the hood ajar switch. An open switch is displayed as Active with the hood Open .

Hour Meter: The scan tool displays 0-10,000 hours. This is the PCM accumulated engine run time hours provided to the IPC via the class 2 serial data link.

Ign. Since Current DTC: The scan tool displays 0-50. The IPC counts the number of times the ignition is cycled since the current DTC was set.

Ignition 1: The scan tool displays Active or Inactive. The scan tool displays Active when the ignition switch is in the RUN or CRANK position

Ignition 3: The scan tool displays Active or Inactive. The scan tool displays Active when the ignition switch is in the RUN position only.

Ignition 1 Signal: The scan tool displays 0 to 16 V. The ignition 1 signal represents the system voltage detected by the PCM at the ignition voltage circuit.

Indicator Type: The scan tool displays On or Off. The IPC determines when to illuminate and what indicator to illuminate based on the class 2 message from the chime module.

Julian Date of Build: The scan tool displays the date upon which the instrument panel cluster (IPC) was manufactured.

Key In Ignition: The scan tool displays Yes or No. The BCM monitors the signal circuit of the ignition key alarm switch. The scan tool displays Yes when the ignition key is fully inserted into the ignition switch cylinder.

Language: The scan tool displays what language is being displayed on the DIC.

Left Rear Cargo Door Ajar Switch: The scan tool displays On or Off. The BCM monitors the signal circuit of the left rear cargo door ajar switch. An open switch is displayed as On with the door open.

Left Turn Input: The scan tool displays Open or Closed. The IPC monitors the left turn signal supply voltage circuit. An active turn signal toggles between Open and Closed.

Low Beam Output: The scan tool displays On or Off. The BCM monitors the low beam output signal. When the low beam switch is turned Off the signal is displayed as Off.

Low Fuel Lamp: The scan tool displays On or Off. The IPC determines when to illuminate the indicator based on the class 2 message from the PCM indicating the fuel level percent.

Low Oil Lamp Command: The scan tool displays On or Off. This the state of the low oil lamp command as monitored by the PCM.

Low Washer Fluid: The scan tool displays On or Off. The IPC monitors the windshield washer solvent level switch, where a closed switch with low washer fluid is displayed as On.

MIL (Malfunction Indicator Lamp) Command: The scan tool displays On or Off. This is the commanded state of the MIL (Malfunction Indicator Lamp) by the PCM.

Monitored Coolant Temp: The scan tool displays -40°C to +215°C (-40°F to +419°F). This is the PCM monitored coolant temperature data as provided to the IPC via the class 2 serial data link.

Monitored Fuel Level: The scan tool displays 0-100%. This is the PCM monitored fuel level percent as provided to the IPC via the class 2 serial data link.

Monitored Oil Pressure: The scan tool displays 0-682 kPa (0-99 psi). The IPC monitored oil pressure as provided by the PCM via the class 2 serial data link.

Over Drive Defeat: The scan tool displays Active or Inactive. This is the state of the over drive defeat indicator as commanded by the IPC.

Park Brake Switch: The scan tool displays Set or Released. The BCM monitors the park brake signal circuit, where a closed switch with the park brake applied is displayed as Set.

Park Lamp Relay: The scan tool displays the commanded state of the park lamp relay. The scan tool displays On when the BCM allows the park lamp relay to go to ground to activate the park lamps.

Park Lamp Switch: The scan tool displays Active or Inactive. The BCM monitors the signal circuit of the parklamp switch. A closed switch is displayed as Active.

Passenger Door Ajar Switch: The scan tool displays On or Off. The BCM monitors the signal circuit of the passenger door ajar switch. An open switch is displayed as On with the door open.

Personalization: The scan tool displays the commanded state of the DIC switches. The scan tool displays FUEL, TRIP, RE/SET, and FUEL ECON.

PRNDL State: The scan tool displays the PRNDL display of the vehicle. This is the state of the PRNDL range as communicated to the IPC by the PCM. The value of this data corresponds to the PRNDL display.

RAP Relay: The scan tool displays On or Off. This is the state of the RAP relay as monitored by the BCM.

Reduced Engine Power: The scan tool displays Inactive or Active. This is the state of the Reduced Engine Power indicator as monitored by the PCM.

Right Rear Door Ajar Switch: The scan tool displays On or Off. The BCM monitors the signal circuit of the right rear door ajar switch. An open switch is displayed as On with the door open.

Right Turn Input: The scan tool displays Open or Closed. The IPC monitors the right turn signal lamps supply voltage circuit. An active turn signal toggles between Open and Closed.

Security Lamp: The scan tool displays On or Off. This is the state of the security lamp indicator as commanded by the IPC in the message center.

Service 4WD: The scan tool displays On or Off. This is the state of the service 4WD indicator as commanded by the IPC.

Software Part Number: The scan tool displays the software identification number (ID) in the IPC.

Software Revision Number: The scan tool displays the latest version of the software in the IPC.

Tow/Haul: The scan tool displays On or Off. This is the state of the Tow/Haul indicator as commanded by the IPC.

Trans. Fluid Temp: The scan tool displays -40°C to +215°C (-40°F to +419°F). This is the PCM monitored transmission fluid temperature data as provided to the IPC via the class 2 serial data link.

Trip Odometer A: The scan tool displays miles. The IPC calculates trip odometer information from the vehicle speed data received from the PCM.

Trip Odometer B: The scan tool displays miles. The IPC calculates trip odometer information from the vehicle speed data received from the PCM.

Trip Reset Switch: The scan tool displays Active or Inactive. The IPC monitors the TRIP RESET button of the DIC switch. A closed switch is displayed as Active.

Upshift Lamp: The scan tool displays On or Off. This is the state of the upshift lamp as commanded by the IPC.

Vehicle Speed Sensor: The scan tool displays kilometers per hour (miles per hour). The IPC receives the vehicle speed from the PCM 4 kppm vehicle speed signal circuit.

Vehicle Speed Sensor: The scan tool displays 0-255 km/h (0-159 mph). The PCM monitors the voltage at the signal circuit of the vehicle speed sensor. The voltage is proportional to the vehicle speed.

Volume: The scan tool displays 0-100%. The volume selected.

Year Model Built:  The scan tool displays 1990-2020. The production year the module was manufactured.