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 1

Ignition

Volts

12.6 Volts

Engine Control Module (ECM)

Scan Tool Parameter

Data List

Units Displayed

Typical Data Value

Ignition ON/Engine OFF/Clutch Depressed or Transmission in Park or Neutral

GEN F-Terminal Signal

General Info - Outputs

%

0%

GEN L-Terminal Signal Command

General Info - Outputs

On/Off

Off

Ignition 1

General Info - Outputs

Volts

12.6 Volts

Starter Relay Command

Output Driver Status

On/Off

Off

Starter Relay - Low Volts

Output Driver Status

Test Pass/Test Fail/Test Not Run

Test Pass

Starter Relay - Open

Output Driver Status

Test Pass/Test Fail/Test Not Run

Test Pass

Starter Relay - High Volts

Output Driver Status

Test Pass/Test Fail/Test Not Run

Test Not Run