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

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 1

Accessory

Volts

0-25 V

Shifter Unlock Fdbk

Accessory

High/Low

High

Engine Control Module (ECM) / Powertrain Control Module (PCM)

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.

Brake Switch

ECM/PCM, General Info - Inputs

Applied/Released

Released

Ignition 1

ECM/PCM, General Info - Inputs

Volts

0-20 V

Transmission Range

ECM, Transmission Data

Reverse, 2nd, Drive, Park, Neutral, 1st, 3rd

Park

TR Sw.

PCM, Transmission Data

Invalid, Park, Reverse, Neutral, Drive, Intermediate, Low

Park