GM Service Manual Online
For 1990-2009 cars only

Engine Control Module (ECM) 7.8L (LG4)

Scan Tool Parameter

Data List

Units Displayed

Typical Data Value

Operating Conditions: Ignition ON/Engine Running

Battery Voltage

Engine 1

Volts

Varies

Clutch Pedal Switch

Engine 1

Applied / Released

Released

Crank Voltage Present

Engine 1

Yes/No

No

GEN L-Terminal Signal

Engine 1

Voltage / No Voltage

Voltage

Ignition 1 Signal

Engine 1

Volts

Varies

PNP Switch

Engine 1

In Gear / Park / Neutral

Park / Neutral

Starter Relay Command

Engine 1

ON / OFF

OFF

Stop Lamp Pedal Switch

Engine 1

Applied / Released

Released