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

0 Amps

Run/Crank Relay

BCM, Power Mode

On/Off

On

Run/Crank Relay Command

BCM, Power Mode

On/Off

On

L61/LE5 Engine Control Module (ECM)

Scan Tool Parameter

Data List

Units Displayed

Typical Data Value

Ignition ON/Engine OFF

Crank Request Signal

ECM, Data Display, Electrical/Theft Data

Yes/No

No

GEN F-Terminal Signal

ECM, Data Display, Electrical/Theft Data

%

0 %

GEN L-Terminal Command

ECM, Data Display, Electrical/Theft Data

%

0 %

GEN L-Terminal Circuit Status

ECM, Data Display, Electrical/Theft Data

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

OK

Ignition 1 Signal

ECM, Data Display, Electrical/Theft Data

Volts

12.6 Volts

Ignition Accessory Signal

ECM, Data Display, Electrical/Theft Data

On/Off

On

Starter Relay Command

ECM, Data Display, Electrical/Theft Data

On/Off

Off

Transmission Control Module (TCM)

Scan Tool Parameter

Data List

Units Displayed

Typical Data Value

Ignition ON/Engine OFF

TR Sw.

Transmission Data, Data Display

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

Park