GM Service Manual Online
For 1990-2009 cars only

Object Number: 866356  Size: MF

The UHFB supplies the solenoid circuits with battery voltage when the ignition is in run. The ABS control module (EBTCM) controls valve function by grounding the solenoid circuit when necessary.

DTC Parameters

The UHFB supplies the solenoid circuits with battery voltage when the ignition is in run. The ABS control module (EBTCM) controls valve function by grounding the solenoid circuit when necessary.

When DTC C0090 sets:

    • The ABS telltale will be on.
    • The red BRAKE telltale will be On.
    • The ABS control module will disable ABS.
    • Dynamic rear proportioning (DRP) will only be functional on one rear wheel. If a LR solenoid or LR wheel speed DTC sets with DTC C0080, then DRP is disabled.

Diagnostic Aids

The ABS control module must be replaced.