BRAKELIGHT Switch Circuit
CAUTION:
If Anti-Lock Brake System/Traction Control/Vehicle Skid Control Electronic Control Unit (ABS/TRAC/VSC ECU) replacement is necessary during testing, always ensure ABS/TRAC/VSC ECU connectors and ground circuit are okay. If either is suspect, repair and repeat testing to confirm ABS/TRAC/VSC ECU malfunction.
- Ensure brakelights operate when brake pedal is depressed. Disconnect brakelight switch connector and remove brakelight switch. Using an ohmmeter, check for continuity between brakelight switch terminals. Continuity should exist between terminals No. 1 and 2. Depress brakelight switch button. Continuity should exist between terminals No. 3 and 4. See Fig 1. Replace switch as necessary. If brakelight switch is okay, go to next step.
- Using a voltmeter, measure voltage between ground and brakelight switch connector terminal No. 2 (White wire). If battery voltage exists, brakelight switch circuit is okay. If battery voltage is not present, check and repair circuit between brakelight switch, power source and ABS/TRAC/VSC ECU. If circuit is okay, replace ABS/TRAC/VSC ECU.