GM Service Manual Online
For 1990-2009 cars only
Table 1: Body Control Module (BCM)
Table 2: Engine Control Module (ECM)

Body Control Module (BCM)

Scan Tool Parameter

Data List

Units Displayed

Typical Data Value

Operating Conditions: Ignition ON, with the Engine OFF. Transmission Shift Lever in the PARK Position.

Battery Voltage Signal

BCM, Power Mode

0-15 volts

12 volts

Brake Lamp Command

BCM, Chassis Data

ON/OFF

ON

Shift Lock Solenoid Command

BCM, Chassis Data

Unlock/Lock

Lock

Engine Control Module (ECM)

Scan Tool Parameter

Data List

Units Displayed

Typical Data Value

Operating Conditions: Ignition ON, with the Engine OFF. Transmission Shift Lever in the PARK Position.

Ignition 1 Signal

ECM, Engine Data

Volts

12 V

TR Sw.

Transmission Data

Park, Reverse, Neutral, Drive 5, Drive 4, Drive 3, Drive 3, Drive 2, Drive 1

Park