Diagnostic Notes

NORMAL OPERATION
Upon receiving ignition voltage, the antilock brake control module lamp driver activates the amber ABS warning lamp for about 1.5 seconds. If all internal checks are OK, the lamp driver is de-energized and the amber ABS warning lamp is turned off.


FAULT DESCRIPTION
Shorted amber ABS warning lamp is generated by the antilock brake control module's detection of battery voltage at antilock brake control module Pin 23 when the amber ABS warning lamp is supposed to be turned on. A dim bulb may intermittently cause the antilock brake control module to set Code C1220 as well.

Connector:

POSSIBLE CONTRIBUTING COMPONENTS/VEHICLE WIRING CONCERNS
- Shorted bulb.
- Short to battery voltage between the amber ABS warning lamp and the antilock brake control module Pin 23.
- Defective lamp driver circuit in the antilock brake control module.