GM Service Manual Online
For 1990-2009 cars only
Accy/RAP Relay Command: The scan tool displays On or Off. This is the state of the Accy/RAP relay command as monitored by the body control module (BCM).

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 instrument panel cluster (IPC).

Brake Fluid: The scan tool displays OK or Low. This is the state of the brake fluid level switch as monitored by the IPC.

Brake Fluid Switch: The scan tool displays 0-5 volts. The IPC monitors the brake fluid switch signal circuit where a low voltage indicates low brake fluid.

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

DIC Information: The scan tool displays Active or Inactive. The IPC monitors the information button of the DIC switch. A closed switch is displayed as Active.

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

Driver Door Ajar Sw.: The scan tool displays Active or Inactive. The driver door module monitors the signal circuit of the driver door ajar switch. An open switch is displayed as Active 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 engine control module (ECM). 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 ECM. A closed switch is displayed as OK.

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

Engine Oil Pressure Sensor: The scan tool displays 0-5 volts. The ECM 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 ECM from the 3X reference input. It should remain close to desired idle under various engine loads with the engine idling.

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

Engine Oil Pressure Switch: The scan tool displays OK or Low. The ECM monitors the signal circuit of the engine oil pressure switch. A closed switch with low oil pressure is displayed as Low.

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 ECM.

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 ECM.

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

Hazard Lamp Switch: The scan tool displays Active or Inactive. The BCM monitors the hazard switch signal circuit. When the hazard lamp is off the signal is displayed as Inactive.

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.

High Beam Relay Command: 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 Select Switch: The scan tool displays Active or Inactive. This is the position of the high beam select switch where an on switch is displayed as Active.

Ign. Off/Run/Crank: The scan tool displays Key Out/ACC/Key In/Off/Crank/Run. The power mode status as monitored by the BCM.

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

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

Ignition Cycle Counter: The scan tool displays 0-255. The IPC counts the number of times the ignition is cycled.

Key In Ignition Status: The scan tool displays Key In or Key Out. The BCM monitors the signal circuit of the ignition key alarm switch. The scan tool displays Key In when the ignition key is fully inserted into the ignition switch cylinder.

LCD Dimming: The scan tool displays 0-100 percent. This is the dimming level of the backlight of the IPC.

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

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

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

MIL Requested By DTC: The scan tool displays Yes or No. This is the parameter that indicates if the commanded state of the MIL was set by a DTC.

MIL Circuit Status: The scan tool displays Short Gnd/Open/Short to B+/OK/Incomplete. The ECM monitors the status of the MIL signal circuit

Odo/Trip Reset Switch: The scan tool displays Active or Inactive. The IPC monitors the trip reset stem on the cluster. A closed switch is displayed as Active.

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

Park Lamp Relay Cmd.: 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 Active or Inactive. The passenger door module monitors the signal circuit of the passenger door ajar switch. An open switch is displayed as On with the door open.

Passenger Seatbelt Indicator Commanded: The scan tool displays On or Off. This is the state of the passenger safety belt indicator as commanded by the IPC.

Passenger Seatbelt Indicator Status: The scan tool displays On or Off. This is the state of the passenger safety belt indicator as monitored by the IPC.

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

Right Rear Door Ajar Sw.: The scan tool displays Door Closed/Door Ajar. The BCM monitors the signal circuit of the right rear door ajar switch. An open switch is displayed as Door Ajar with the door open.

Set/Reset Switch: The scan tool displays Active/Inactive. The IPC monitors the set/reset button of the DIC switch. A closed switch is displayed as Active.

TR Sw.: The scan tool displays Park/Reverse/Neutral/Drive. The gear position status as monitored by the ECM.

Trans. Fluid Temp: The scan tool displays -40°C to +215°C (-40°F to +419°F). This is the ECM monitored transmission fluid temperature data.

Vehicle Speed Circuit 2 Status: The scan tool displays Short Gnd/Open/Short to B+/OK/Incomplete. The ECM monitors the status of the vehicle speed signal circuit

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

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