GM Service Manual Online
For 1990-2009 cars only

Powertrain Control Module (PCM)

Scan Tool Parameter

Data List

Units Displayed

Typical Data Value

Ignition ON/Engine OFF

Crank Request Signal

Engine 3

Yes/No

No

Generator L Terminal Signal

Engine 2

Voltage/No Voltage

No Voltage

Generator F Terminal Signal

Engine 2

%

10 - 90%

Ignition 1 Signal

Engine 1,2,3

Volts

9.6 - 14.4 V

Starter Relay Command

Engine 3

Off/On

Off

TR Sw.

Transmission Data

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

Park