GM Service Manual Online
For 1990-2009 cars only

Engine Control Module (ECM)/Powertrain Control Module (PCM)

Scan Tool Parameter

Data List

Units Displayed

Typical Data Value

Operating Conditions: Ignition ON/Engine OFF (Gasoline Engines Only)

GEN F--Terminal Signal

Engine Data 2

%

10-90%

GEN L--Terminal Signal Command

Engine Data 2

On/Off

On

Ignition 1 Signal

Engine Data 1, Engine Data 2

Volts

9-14 V

Operating Conditions: Ignition ON/Engine OFF (Diesel Engines Only)

GEN L--Terminal Signal

Engine Data 1

Voltage/No Voltage

Voltage

Ignition 1 Signal

Engine Data 1

Volts

9-14 V