GM Service Manual Online
For 1990-2009 cars only

Circuit Description


Object Number: 901597  Size: MF

The PCM receives messages from the ABS controller to activate the traction control system. When messages are not transmitted properly between the ABS controller and PCM, a DTC P1602 will set.

Conditions for Setting the DTC

Important: The ABS controller circuit is continuously checked when the ignition is ON.

DTC P1602 will set if:

    • No message is received from the ABS controller
        OR
    • A certain number of incorrect messages have been sent to the PCM.

Diagnostic Aids

    • Check the tightness of the female terminal grip with a spare male terminal.
    • If DTC P1602 is set, traction control will be disabled.

Object Number: 902500  Size: FP