GM Service Manual Online
For 1990-2009 cars only
Table 1: ECM
Table 2: IPC

ECM

Scan Tool Output Control

Additional Menu Selection(s)

Description

GEN L-Terminal

Special Functions, Engine Output Controls

The engine control module (ECM) / powertrain control module (PCM) commands the generator OFF by removing the 5-volt reference signal from the L terminal of the voltage regulator when you select OFF. The generator will then stop generating an output voltage.

IPC

Scan Tool Output Control

Additional Menu Selection(s)

Description

Lamp and Gage Check

Body, Instrument Panel Cluster, Special Functions

The instrument panel cluster (IPC) illuminates the following indicators when you select ON:

    • ABS
    • Air Bag
    • BRAKE
    • Charge
    • Fasten Safety Belt
    • High Beam
    • Low Oil Pressure
    • LOW TRAC
    • Upshift Indicator

The IPC drives the following gages to maximum position when you select ON:

    • Engine Coolant Temperature Gage
    • Fuel Gage
    • Speedometer
    • Tachometer

The indicators should stay illuminated and all gages remain at maximum until commanded OFF. When commanded OFF, the indicators should turn OFF and all gages should remain at the minimum position until the test is exited or commanded ON.