GM Service Manual Online
For 1990-2009 cars only

Object Number: 866409  Size: MF

The ABS control module (EBTCM) functions properly within a specified range of voltage. During ABS and traction control operation there are current requirements that will cause the system voltage to drop. Because of this, the EBTCM continuously monitors system voltage for a good charging system and for a high voltage that could damage the system.

DTC Parameters

DTC C0900 will set if:

Vehicle speed is greater than 8 km/h (5 mph), and solenoid relay voltage is greater than 19 volts for 0.72 seconds:

When this trouble code sets, the EBTCM will disable ABS and turn On the antilock telltale.

Dynamic rear proportioning (DRP) will only have the hold function.

Diagnostic Aids

Check for following conditions:

    • Charging system malfunction
    • For complete information and additional diagnostics for the vehicle charging system, refer to Starting and Charging.