GM Service Manual Online
For 1990-2009 cars only
Table 1: PCM - 3.8L
Table 2: PCM - 4.6L

PCM - 3.8L

Scan Tool Output Control

Additional Menu Selection(s)

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, 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 to activate or deactivate the cooling fan 1 relay, 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.

PCM - 4.6L

Scan Tool Output Control

Additional Menu Selection(s)

Description

Fan Control 1 and 2

Fan Relays

The scan tool displays a Commanded State of Off, Low or High. This allows you to communicate with the PCM to activate or deactivate the cooling fan relays, manually turning the low speed fans or high speed fans.