System Precheck
DIAGNOSTIC TROUBLE CODES: C1225, C1226NORMAL OPERATION
Upon receiving ignition voltage, the ECU lamp driver activates the red BRAKE warning lamp for about 1.5 seconds. If all internal checks are OK, the lamp driver is de-energized and the red brake warning lamp is turned OFF.
Connector:
FAULT DESCRIPTION
Shorted BRAKE lamp is generated by the ECU's detection of B+ voltage to the ECU red BRAKE lamp input pin 16 when the brake lamp is supposed to be turned ON.
Foundation brake system fault is generated by the ECU's detection of low voltage on pin 16 of the ECU when the lamp is not energized by the ECU.
POSSIBLE CONTRIBUTING COMPONENTS/VEHICLE WIRING CONCERNS:
C1225
- Shorted bulb.
- Short to vehicle battery voltage in the wiring between the 4WABS lamp and the ECU.
- Defective lamp driver circuit in the ECU.
C1226
- Low fluid.
- Short to ground at ECU pin 16.
- Defective lamp driver circuit in the ECU.
- Defective bulb check switch (IGN crank only).