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 Running

Battery Voltage

Data

Volts

12.6 Volts

Regulated Voltage Control Current Sensor

Data

%

0 %

Starter Switch

Inputs

Released/Cranking

Released

Instrument Panel Cluster (IPC)

Scan Tool Parameter

Data List

Units Displayed

Typical Data Value

Ignition ON/Engine Running

Battery Voltage

Data

Volts

12.6 Volts

Powertrain Control Module (PCM)

Scan Tool Parameter

Data List

Units Displayed

Typical Data Value

Ignition ON/Engine OFF/Transmission in Park

Crank Request Signal

Data Display

Yes/No

No

GEN F-Terminal Signal

Data Display

%

45%

GEN L-Terminal Signal Command

Data Display

On/Off

OFF

Ignition 1 Signal

Data Display

Volts

12.6 Volts

IMS

Transmission Data

Drive 3, Drive 4\Drive 3, Park\Reverse, Reverse, Drive 3\Drive 2, Drive 2, Park, Invalid, Neutral\Drive 4, Drive 4, Neutral, Reverse\Neutral, Drive 1, Drive 2\Drive 1, Invalid, Open

Park

Starter Relay Circuit History

Data Display

OK/Open/Short/Invalid

OK

Starter Relay Command

Data Display

On/Off

Off

Engine Control Module (ECM)

Scan Tool Parameter

Data List

Units Displayed

Typical Data Value

Ignition ON/Engine OFF/Transmission in Park

Crank Request Signal

Data Display

Yes/No

No

Current Gear

Data Display

P/N, 1st, 2nd, 3rd, 4th, 5th, Reverse

P/N

GEN F-Terminal Signal

Data Display

%

45%

GEN L-Terminal Signal Command

Data Display

%

10%

Ignition 1 Signal

Data Display

On/Off

Off

IMS

Transmission Data

Drive 3, Drive 4\Drive 3, Park\Reverse, Reverse, Drive 3\Drive 2, Drive 2, Park, Invalid, Neutral\Drive 4, Drive 4, Neutral, Reverse\Neutral, Drive 1, Drive 2\Drive 1, Invalid, Open

Park

PNP Switch

Data Display

Park/Neutral, In Gear

Park/Neutral

Starter Relay Command

Data Display

On/Off

Off