GM Service Manual Online
For 1990-2009 cars only
4WD Signal (If Equipped): The scan tool displays Enabled or Disabled. The powertrain control module (PCM) monitors the signal circuit of the 4WD switch. A closed switch is displayed as Enabled.

4WD Low Signal (If Equipped): The scan tool displays Enabled or Disabled. The PCM monitors the signal circuit of the 4WD low switch. A closed switch is displayed as Enabled.

8-Digit GM Part Number: The scan tool displays the GM part number of the instrument panel cluster (IPC).

ABS Lamp: The scan tool displays On or Off. 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 -50 to +50. The Balance between the right and left audio output.

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

Battery Voltage: The scan tool displays 0-19 volts. The voltage measured at the battery positive voltage circuit of the body control module (BCM).

Battery Voltage: The scan tool displays 0-19 volts. The voltage measured at the battery positive voltage circuit of the IPC.

Battery Voltage: The scan tool displays 0-19 volts. The voltage measured from the radio or amplifiers ignition positive voltage circuit to ground.

Battery Voltage Signal: The scan tool displays 0-19 volts. The voltage measured at the battery positive voltage circuit of the RDM.

Brake Lamp: The scan tool displays On or Off. The state of the brake system indicator as commanded by the IPC.

Check Gages Lamp: The scan tool displays On or Off. The state of the CHECK GAGES indicator as commanded by the IPC.

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

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

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

Displayed Coolant Temperature: The scan tool displays 38°C-128°C (100°F-260°F). The displayed coolant temperature gage value in the IPC. This value may slightly differ from the monitored coolant temperature.

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

Displayed Odometer: The scan tool displays 0-999999 km (miles). The displayed odometer value 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.

Driver Door Ajar Switch: The scan tool displays Door Ajar/Door Closed. This is the state of the driver door ajar switch, where a closed switch with the door open is displayed as Door Closed.

ECT Sensor: The scan tool displays -40 to +151°C (-40 to +304°F). The PCM monitors the voltage at the signal circuit of the engine coolant temperature sensor. The voltage is inversely proportional to the engine coolant temperature.

Engine Oil Level Switch: The scan tool displays Ok or Low. The PCM monitors the signal circuit of the engine oil level and temperature sensor. A closed switch is displayed as Low with low engine oil level.

Engine Oil Life Remaining: The scan tool displays 0-100%. The PCM calculates the remaining engine oil life.

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

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

Engine Speed: The scan tool displays 0-9999 RPM. The PCM computes the engine speed. It should remain close to desired idle under various engine loads with the engine idling.

Fade: The scan tool displays -50 to +50. The Fade between the front and rear audio output.

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

Fuel Level Sensor: The scan tool displays 0-5 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 0-5 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 0-100%. 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.

Headlamp Switch:  The scan tool displays Active or Inactive. The BCM monitors the signal circuit of the head lamp 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. 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.

Ignition 0: The scan tool displays On or Off. The state of the ignition 0 voltage circuit as monitored by the BCM.

Ignition 1: The scan tool displays On or Off. The state of the ignition 1 voltage circuit as monitored by the BCM.

Ignition 1: The scan tool displays 0-19 volts. The voltage measured at the ignition 1 voltage circuit of the IPC.

Ignition 1 Signal: The scan tool displays 0-19 volts. The voltage measured at the ignition 1 voltage circuit of the PCM.

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.

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 key in ignition switch. A closed switch is displayed as Yes with the key in the ignition.

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 state of the low fuel indicator as commanded by the IPC.

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 OK or Low. The state of the low washer fluid switch as monitored by the IPC.

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 Temperature: The scan tool displays 40°F-419°F (40°C-215°C). The IPC monitored coolant temperature data as provided by the PCM via the class 2 serial data link.

Monitored Fuel Level: The scan tool displays 0-100%. The IPC monitored fuel level percent as provided by the PCM 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.

Park Brake Switch:  The scan tool displays Set or Released. The BCM monitors the signal circuit of the park brake switch. A closed switch 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.

Parklamp 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 Door Ajar/Door Closed. This is the state of the passenger door ajar switch, where a closed switch with the door open is displayed as Door Closed.

PRNDL State: The scan tool displays Park, Reverse, Neutral, Drive, 1st, 2nd or 3rd. The state of the PRNDL as commanded by the IPC.

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

Rear Compartment Lid Ajar: The scan tool displays Ajar/Closed. The state of the rear compartment lid ajar switch as monitored by the RDM.

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 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. The state of the SECURITY 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.

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.

Vehicle Speed: The scan tool displays 0-255 km/h (0-155 mph). The IPC monitors the vehicle speed signal circuit from the PCM.

Vehicle Speed Sensor: The scan tool displays 0-255 km/h (0-155 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 percentage of volume selected at the radio.

Year Model Built: The scan tool displays the 4-digit number which corresponds to the year that the IPC was manufactured.