GM Service Manual Online
For 1990-2009 cars only

Body Control Module (BCM)

Scan Tool Parameter

Data List

Units Displayed

Typical Data Value

Ignition ON/Engine OFF

Battery Voltage

Data

Volts

12.6 Volts

Crank

Inputs

Yes/No

No

Instrument Panel Cluster (IPC)

Scan Tool Parameter

Data List

Units Displayed

Typical Data Value

Ignition ON/Engine OFF

Crank

Data

Yes/No

No

Volt Lamp

Inputs

On/Off

Off

Powertrain Control Module (PCM)

Scan Tool Parameter

Data List

Units Displayed

Typical Data Value

Ignition ON/Engine OFF

Crank Request Signal

Engine Data 2

Yes/No

No

GEN L-Terminal Signal Command

Engine Data 2

On/Off

Off

Ignition 1 Signal

Engine Data 1, Engine Data 2

Volts

12.6 Volts

Starter Enable Relay Circuit Status

Outputs

OK/Fault/Invalid State

OK

Starter Relay Command

Engine Data 2

On/Off

Off

Transmission Control Module (TCM)

Scan Tool Parameter

Data List

Units Displayed

Typical Data Value

Ignition ON/Engine OFF/Transmission in Park

IMS

Transmission Data

Park, Park/Reverse, Reverse, Reverse/Neutral, Neutral, Neutral/Drive 4, Drive 4, Drive 4/Drive 3, Drive 3, Drive 3/Drive 2, Drive 2, Drive 2/Drive 1, Drive 1, INVALID

Park