GM Service Manual Online
For 1990-2009 cars only

Powertrain Control Module

Scan Tool Output Control

Additional Menu Selections

Description

Fans Low Speed

Fan Relays

The scan tool displays a commanded state of NONE, OFF, or ON. This allows you to communicate with the PCM and activate or deactivate the cooling fan 1 relay, by manually turning the low speed fans ON and OFF.

Fans High Speed

Fan Relays

The scan tool displays a commanded state of NONE, OFF, or ON. This allows you to communicate with the PCM and activate or deactivate the cooling fan 1 relay, by manually turning the low speed fans ON. After a 3-second delay the PCM will activate the cooling fan s/p relay and the cooling fan 2 relay. This turns the high speed fans ON and OFF.