Circuit Description
This DTC is used to identify the conditions of the brake switch circuit. The electronic brake control module (EBCM) sends a low current 5-volt sense voltage on brake switch input line to the rear brake light bulbs. If the rear brake light circuit is intact, this voltage will be pulled low, under 1 volt, to ground through the rear brake light bulbs. When the brake light switch is depressed, battery voltage will be supplied to the rear brake lights and to the EBCM, indicating the brake lights are ON. DTC C0093 can be set if test DTC C0091 failed the previous ignition cycle. Once DTC C0093 is set, it will be reset each ignition cycle until a brake switch input is seen.
Conditions for Setting the DTC
| • | Brake switch contacts open |
| • | Brake switch fuse open |
| • | Brake switch fuse power feed circuit open |
| • | Brake switch misadjusted |
| • | Internal EBCM fault |
Action Taken When the DTC Sets
The antilock brake system (ABS) remains functional.
Conditions for Clearing the DTC
| • | If the conditions that set the DTC C0093 are no longer present, the DTC can be cleared by scan tool. |
| • | The DTC that has not occurred in 100 drive cycles will be cleared from the history data. |
Step | Action | Yes | No |
|---|---|---|---|
1 | Did you perform the Diagnostic System Check-ABS? | Go to Step 2 | |
2 |
Did you find other DTC C0091? | Go to DTC C0091 | Go to Step 3 |
3 |
Did you find DTC C0091? | Go to DTC C0091 | Go to Step 4 |
4 | Perform the Diagnostic System Check-ABS. Did you find any DTCs? | Go to the appropriate DTC tables | System OK |
