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 Signal

BCM/Power Mode

Volts

12.6 Volts

Idle Boost Level

BCM/Power Mode

Amps

27 Amps

Run/Crank Relay

BCM/Power Mode

Active/Inactive

Inactive

Run/Crank Relay Command

BCM/Power Mode

On/Off

On

Engine Control Module (ECM)

Scan Tool Parameter

Data List

Units Displayed

Typical Data Value

Ignition ON/Engine OFF

Crank Request Signal

Electrical/Theft Data

Yes/No

No

GEN F-Terminal Signal

Electrical/Theft Data

%

0%

GEN-L Terminal Circuit Status

Electrical/Theft Data

Incomplete, Short Gnd / Open, Short to B+, OK

OK

GEN L-Terminal Signal Command

Electrical/Theft Data

On/Off

Off

Ignition 1 Signal

Electrical/Theft Data

Volts

12.6 Volts

Ignition Accessory Signal

Electrical/Theft Data

On/Off

On

Starter Relay Circuit Status

Electrical/Theft Data

Incomplete, Short Gnd / Open, Short to B+, OK

OK

Starter Relay Command

Electrical/Theft Data

On/Off

Off

Transmission Control Module (TCM)

Scan Tool Parameter

Data List

Units Displayed

Typical Data Value

Ignition ON/Engine OFF

IMS

Transmission Data

Invalid, Drive 3\Drive 2, Drive 2, Reverse\Neutral, Neutral, Drive 5, Park\Reverse, Park, Drive 3, Drive \Drive 3, Reverse, Park\Reverse, Drive 5\Drive 4, Drive 4

Park