Turn Signal Lamps
NOTE:
The turn signal switch is integral to the multi-function switch/SCM, which communicates with the BCM over the CAN data bus. Before performing any of the following tests, determine whether the other functions of the multi-function switch/SCM are operational. If the other multi-function switch/SCM functions are ineffective, diagnose and repair that problem before attempting to repair the Turn Signal Lamps.
| CONDITION | POSSIBLE CAUSES | CORRECTION |
|---|---|---|
| ONE TURN SIGNAL LAMP DOES NOT ILLUMINATE | 1. Ineffective or missing bulb. | 1. Test and replace turn signal bulb if required. |
| 2. Ineffective ground circuit. | 2. Test and repair open ground circuit if required. | |
| 3. Ineffective feed circuit. | 3. Test and repair open right or left turn signal feed circuit if required. | |
| 4. Ineffective BCM inputs or outputs. | 4. Use a diagnostic scan tool to test the BCM inputs and outputs. Refer to the appropriate diagnostic information. | |
| ALL RIGHT SIDE OR ALL LEFT SIDE TURN SIGNAL LAMPS (OR BOTH SIDES) DO NOT FLASH | 1. Ineffective feed circuit. | 1. Test and repair open right or left turn signal feed circuit if required. |
| 2. Ineffective SCM inputs or outputs. | 2. Use a diagnostic scan tool and the appropriate diagnostic information for further SCM diagnosis. | |
| 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. | |
| ALL RIGHT SIDE OR ALL LEFT SIDE TURN SIGNALS FLASH TOO RAPIDLY (MORE THAN 100 FLASHES PER MINUTE) | 1. Ineffective or missing bulb. | 1. Test and replace turn signal bulb if required. |
| 2. Ineffective ground circuit. | 2. Test and repair open bulb ground circuit if required. | |
| 3. Ineffective feed circuit. | 3. Test and repair open right or left turn signal feed circuit if required. | |
| TURN SIGNALS DO NOT AUTOMATICALLY CANCEL | 1. Ineffective cancel cam. | 1. Inspect and replace the turn signal cancel cam (SCCM) if required. |
| 2. Ineffective cancel actuator. | 2. Inspect and replace the turn signal cancel actuator (SCCM) if required. |