Brake Lamps
| CONDITION | POSSIBLE CAUSES | CORRECTION |
|---|---|---|
| BRAKE LAMP DOES NOT ILLUMINATE | 1. Ineffective or missing bulb. | 1. Test and replace brake lamp bulb if required. |
| 2. Ineffective ground circuit. | 2. Test and repair open brake lamp ground circuit if required. | |
| 3. Ineffective fuse. | 3. Test and replace the fuse if required. | |
| 4. Inspect power and ground at the switch. | 4. Verify power and ground to the switch. Repair as needed. | |
| 5. Ineffective feed circuit. | 5. Test and repair open brake lamp switch output circuit or stop lamp output circuit if required. | |
| 6. Ineffective switch. | 6. Inspect, test and replace brake lamp switch if required. Review graphic shown below for proper tab alignment. | |
| 7. Ineffective BCM inputs or outputs. | 7. Use a diagnostic scan tool to test the BCM inputs and outputs. Refer to the appropriate diagnostic information. | |
| BRAKE LAMP DOES NOT EXTINGUISH | 1. Ineffective feed circuit. | 1. Test and repair shorted brake lamp switch output circuit or stop lamp output circuit if required. |
| 2. Ineffective brake lamp switch. | 2. Test and replace brake lamp switch if required. Review graphic shown below for proper tab alignment. | |
| 3. Ineffective BCM inputs or outputs. | 3. Use a diagnostic scan tool to test the BCM inputs and outputs. Refer to the appropriate diagnostic information. |
The following descriptions align with the graphic callouts above of the brake lamp switch.
- Defective brake lamp switch due to the switch tab being sheared off.
- Defective brake lamp switch due to the switch tab being offset.
- Normal operational brake lamp switch to be used for installation.
NOTE:
If damage to the brake lamp switch is present for any reason the switch must be replaced. If a switch is removed and the plunger length differs from a new switch, the switch should be replaced and not reinstalled. The nominal height for a new switch (tip of the plunger to the body of the switch) is 16.90 mm.