Circuit Description
This DTC is the second portion of DTC C1291. If DTC C1291 occurred during an ignition cycle, DTC C1293 becomes a current malfunction during the next ignition cycle, keeping TCS disabled until a brake switch on state is seen. When a change is seen during an ignition cycle in which DTC C1293 is a current malfunction, DTC C1291 will clear itself at the end of the current ignition cycle, and TCS will enable itself at the start of the next ignition cycle. DTC C1293 alone indicates DTC C1291 occurred previously, but is intermittent, or has been corrected.
Conditions for Running the DTC
The ABS conditions and the braking conditions are normal.
Conditions for Setting the DTC
DTC C1293 is set when DTC C1291 was set in the previous or current ignition cycle.
Action Taken When the DTC Sets
| • | The EBCM disables the TCS for the duration of the ignition cycle. |
| • | The Traction Off indicator turns ON. |
| • | The message center displays the Service Traction System message. |
| • | The ABS remains functional. |
Conditions for Clearing the DTC
| • | Condition for DTC is no longer present and scan tool clear DTC function is used. |
| • | 100 ignition cycles have passed with no DTCs detected. |
Diagnostic Aids
| • | Possible causes: |
| - | Stoplamp switch fuse open. |
| - | Stoplamp switch contacts open. |
| - | Stoplamp switch misadjusted. |
| - | Stoplamp switch fuse power feed circuit open. |
| • | It is very important that a thorough inspection of the wiring and connectors be performed. Failure to carefully and fully inspect wiring and connectors may result in misdiagnosis, causing part replacement with reappearance of the malfunction. |
| • | An intermittent malfunction is most likely caused by a poor connection, rubbed through wire insulation, or a wire that is broken inside the insulation. |
| • | Also, verify proper stoplamp switch operation using the Data List of the scan tool. As the brake is applied, the data list should display the stoplamp switch on within 1 inch of travel. |
Step | Action | Value(s) | Yes | No |
|---|---|---|---|---|
1 | Did you perform the ABS Diagnostic System Check? | -- | Go to Step 2 | |
2 |
Does the scan tool display the DTC C1291 set as current or history? | -- | Go to DTC C1291 Open Brake Lamp Switch Contacts During Deceleration |
