Circuit Description
This DTC is used in order to identify open stoplamp switch circuitry that prevents the stoplamp switch input from changing states when the brake is applied. This DTC is used in conjunction with DTC C1291 in order to determine the cause of an open stoplamp switch malfunction.
Conditions for Setting the DTC
This DTC sets after the following occur:
| • | Initialization is completed. |
| • | The stoplamp/BTSI switch input voltage is out of specification for 1 second (indicating an open circuit). |
Action Taken When the DTC Sets
| • | A DTC C1295 is stored |
| • | The TCS is disabled. |
| • | The TRACTION OFF indicator is turned on |
| • | The ABS remains functional |
Conditions for Clearing the DTC
| • | The condition for the DTC is no longer present and you used the scan tool Clear DTC function. |
| • | The EBCM/EBTCM does not detect the DTC in 50 drive cycles. |
Diagnostic Aids
| • | Thoroughly inspect the wiring and the connectors. Failure to carefully and fully inspect the wiring and the connectors may result in misdiagnosis. Misdiagnosis may cause part replacement without repairing the malfunction. |
| • | The following conditions may cause an intermittent malfunction: |
| - | A poor connection |
| - | Rubbed through wire insulation |
| - | A wire broken inside the insulation |
| • | The following conditions are other possible causes for this malfunction: |
| - | An open in the stoplamp/BTSI switch input circuit |
| - | An open in all of the brake lamps |
| - | An open or maladjusted brake lamp switch |
| - | A wiring problem, terminal corrosion or a poor connection in the circuit |
| • | If an intermittent malfunction exists, refer to Testing for Electrical Intermittents in Wiring Systems. |
Test Description
The numbers below refer to the step numbers on the diagnostic table.
Step | Action | Value(s) | Yes | No |
|---|---|---|---|---|
1 | Was the ABS Diagnostic System Check performed? | -- | Go to Diagnostic System Check | |
2 | Press the brake pedal. Do the brake lights come on? | -- | ||
Is the voltage within specifications? | Battery Voltage | |||
4 | Replace the EBTCM. Refer to Electronic Brake Control Module Replacement . Is the replacement complete? | -- | Go to Diagnostic System Check | -- |
5 | Repair the open or high resistance in CKT 20. Refer to Wiring Repairs in Wiring Systems. Is the circuit repair complete? | -- | Go to Diagnostic System Check | -- |
6 | Check the STOP fuse in the underhood fuse block. Is the fuse OK? | -- | ||
7 |
Is the voltage within specifications? | Battery Voltage | ||
8 | Repair the open in CKT 640. Refer to Wiring Repairs in Wiring Systems. Is the circuit repair complete? | -- | Go to Diagnostic System Check | -- |
Connect a fused jumper wire between the Stoplamp/BTSI switch harness connector terminals A and B. Do the brake lamps come on? | -- | |||
10 | Adjust or repair the stoplamp/BTSI switch as necessary. Refer to Stop Lamp Switch Adjustment or Stop Lamp Switch Replacement in Hydraulic Brakes. Is the repair complete? | -- | Go to Diagnostic System Check | -- |
11 |
Is the fuse OK? | -- | ||
12 | Repair the short to ground in CKT 640. Refer to Wiring Repairs in Wiring Systems. Is the circuit repair complete? | -- | Go to Diagnostic System Check | -- |
13 |
Is the fuse OK? | -- | Go to Diagnostic System Check | |
14 |
Is the fuse OK? | -- | ||
15 | Repair the short to ground in CKT 20. Refer to Wiring Repairs in Wiring Systems. Is the circuit repair complete? | -- | Go to Diagnostic System Check | -- |
