Circuit Description
DTC C1293 is the second portion of DTC C1291 and DTC C1292. If DTC 1291 or DTC 1292 failed during the last ignition cycle, DTC C1293 becomes a current failure during the next ignition cycle. DTC C1293 failure keeps ABS/TCS disabled until identifying a brake switch on state. When identifying a change during an ignition cycle in which DTC C1293 is a current malfunction, DTC C1291 or DTC 1292 will clear itself at the end of the current ignition cycle. ABS/TCS will then enable itself at the start of the next ignition cycle. DTC C1293 alone indicates DCT C1291 or DTC C1292 failed previously, but is intermittent, or has been corrected.
Diagnostic Aids
Use the enhanced diagnostic function of the Scan Tool in order to measure the frequency of the malfunction. Refer to the Scan Tool manual or Scan Tool Diagnostics located in this section for the procedure. Use the Data List of the Scan Tool verify proper brake switch operation. The Data List should display the brake switch as the brake is applied within 25 mm (1.0 in) of brake pedal travel.
Thoroughly inspect any circuitry that may cause the intermittent complaint for the following conditions:
| • | Rubbed-through wire insulation |
| • | A broken wire inside the insulation |
| • | Backed out terminals |
| • | Improper mating |
| • | Broken locks |
| • | Improperly formed or damaged terminals |
| • | Poor terminal-to-wiring connections |
| • | Physical damage to the wiring harness |
Important: Zero the J 39200 test leads before making any resistance measurements.
Step | Action | Value(s) | Yes | No |
|---|---|---|---|---|
1 | Was the Diagnostic System Check performed? | -- | Go to Diagnostic System Check | |
2 |
Is DTC C1291 or DTC C1292 set as either a current and/or a history DTC? | -- | Go to DTC C1291 Open Brake Lamp Switch Contacts During Deceleration or DTC C1292 Open Brake Lamp Switch When ABS Was Required | |
3 |
Did DTC C1293 clear? | -- | Go to Diagnostic System Check | |
4 | Replace the EBCM/EBTCM. Refer to Electronic Brake and Traction Control Module Replacement . Is the repair complete? | -- | Go to Diagnostic System Check | -- |
