GM Service Manual Online
For 1990-2009 cars only
Battery Voltage: The scan tool displays the system voltage of the vehicle.

Brake Fluid: The scan tool displays OK/Low. This is the state of the vehicle brake fluid as monitored by the instrument panel cluster (IPC).

Brake Fluid Switch: The scan tool displays 0-5 volts. This is the state of the brake fluid switch as monitored by the IPC.

Cruise Control Active: The scan tool displays Yes/No. This is the status of the cruise control switch as commanded by the engine control module (ECM).

Change Engine Oil Indicator Command: The scan tool displays Off or On. This is the state of the change engine oil indicator as commanded by the ECM.

DIC Fuel Information: The scan tool displays Active/Inactive. This is the status of the DIC fuel information as monitored by the IPC.

DIC Information Switch: The scan tool displays Active/Inactive. This is the status of the DIC information switch as monitored by the IPC.

DIC Personalization: The scan tool displays Active/Inactive. This is the status of the driver information center (DIC) personalization functions as monitored by the IPC.

ECT Sensor: The scan tool displays -40 to +151°C (-40 to +304°F). The ECM 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. This is the status of the engine oil level switch as monitored by the ECM.

Engine Oil Life Remaining: The scan tool displays 100-0%. This is the engine oil life data as monitored by the ECM.

Engine Oil Pressure Switch: The scan tool displays OK/Low. This is the state of the engine oil pressure sensor as monitored by the ECM.

Engine Oil Temperature Calculated: The scan tool displays Celsius/Fahrenheit. This is the temperature of the engine oil as calculated by the ECM.

Engine Speed: The scan tool displays 0-9999 RPM. Engine speed is computed by the ECM. 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 signal circuit of the fuel level sensor.

Fuel Tank Level Remaining: The scan tool displays 0-100%. The ECM calculates the amount of fuel remaining based on the signal circuit voltage of the fuel level sensor.

Heated Washer Fluid Indicator Signal: The scan tool displays Active/Inactive. This is the status of the heated washer fluid indicator signal as monitored by the IPC.

Ignition 1 Signal: The scan tool displays the system voltage of the vehicle.

Ignition Accessory Signal: The scan tool displays On or Off. The scan tool displays On when there is voltage present at the ignition accessory signal circuit.

Information Down Switch: The scan tool displays Active/Inactive. This is the state of the DIC information down switch as monitored by the IPC.

Information Down Switch: The scan tool displays Active/Inactive. This the state of the DIC information up switch as monitored by the IPC.

Low EOP Indicator Command: The scan tool displays On or Off. This is the state of the low EOP indicator as monitored by the ECM.

Low Engine Oil Level Indicator Command: The scan tool displays On or Off. This is the state of the low engine oil level indicator as monitored by the ECM.

MIL Circuit Status: The scan tool displays Incomplete/Short to GND/Open/Short to B+/Ok. The status of the MIL circuit as monitored by the ECM.

MIL Command: The scan tool displays On or Off. The status of the MIL indicator as commanded by the ECM.

PRNDL: The scan tool displays Invalid/First Gear/Second Gear/Third Gear/Reverse/Neutral/Park/Drive. This is the state of the transmission range as monitored by the ECM.

Passenger Seatbelt Indicator Command: The scan tool displays On or Off. This is the state of the seatbelt indicator command as monitored by the IPC.

Passenger Seatbelt Indicator Status: The scan tool displays On or Off. This is the status of the seatbelt indicator status as monitored by the IPC.

Vehicle Speed Sensor: The scan tool displays 0-255 km/h (0-155 mph). The ECM monitors the signal circuit of the vehicle speed sensor.

Washer Fluid Level: The scan tool displays OK or Low. This is the status of the washer fluid level as monitored by the IPC.