For 1990-2009 cars
ABS Components
Antilock Brake System Schematics
Power Distribution Schematics
Exterior Lights Schematics Domestic
Cruise Control Schematics
Handling Electrostatic Discharge Sensitive Parts Notice

### Circuit Description

This DTC occurs when internal self-checking safety logic has determined that the Stoplamp Switch is continuously on. This is important because the TCS can not be activated when the Stoplamp Switch is on.

### Conditions for Running the DTC

The vehicle speed is greater than 40 km/h (25 mph).

### Conditions for Setting the DTC

DTC C1294 can be set if the vehicle speed reaches at least 40 km/h (25 mph). If the brake lamp switch is always on during two consecutive drive cycles, a malfunction exists.

### Action Taken When the DTC Sets

• | A malfunction DTC is stored.

• | TCS is disabled.

• | Traction Control indicator is turned on.

• | 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 circuit shorted to voltage.

- | Stoplamp switch misadjusted or shorted.

- | Sticking contacts inside stoplamp switch.

- | Binding pedal.

• | 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.

#### DTC C1294 Brake Lamp Switch Circuit Always Active

Step | Action | Value(s) | Yes | No
--- | --- | --- | --- | ---
1 | Did you perform the ABS Diagnostic System Check? | -- | Go to Step 2 | Go to Diagnostic System Check - ABS
2 | Observe the rear brake lamps. Are the brake lamps illuminated without pressure applied to the brake pedal? | -- | Go to Step 3 | Go to Step 4
3 | Disconnect the Stoplamp switch connector C1. Are the brake lamps still illuminated? | -- | Go to Step 5 | Go to Step 6
4 |

1. Disconnect the EBCM harness connector.
2. Install J 39700 Universal Pinout Box using the J 39700-99 Cable Adapter to the EBCM harness connector only.
3. Measure the voltage between the stoplamp switch input circuit at the Universal Pinout Box and a known good ground.

Is any voltage present on the stoplamp switch input circuit without pressure applied to the brake pedal?

--

Go to Step 5

Go to Step 7

5 | Repair a short to voltage in the stoplamp switch input circuit. Refer to Wiring Repairs in Wiring Systems. Did you complete the repair? | -- | Go to Step 9 | --
6 | Adjust or replace the Stoplamp switch as necessary. Refer to Stop Lamp Switch Adjustment or Stop Lamp Switch Replacement in Hydraulic Brakes. Did you complete the repair? | -- | Go to Step 9 | --
7 |

1. Reconnect all connectors.
2. Install a scan tool.
3. Select the ABS Data Display.
4. Carefully drive vehicle for two drive cycles while monitoring the brake input data on the scan tool.

(NOTE: A drive cycle consists of starting the engine, driving above 40 km/h (25 mph) back to 0 km/h (0 mph) and then turning the ignition OFF.)

Was DTC C1294 set in the last two drive cycles?

--

Go to Step 8

System OK

8 | Replace the EBCM. Refer to Electronic Brake Control Module Replacement . Did you complete the repair? | -- | Go to Step 9 | --
9 |

1. Use the scan tool in order to clear the DTCs.
2. Operate the vehicle within the Conditions for Running the DTC as specified in the supporting text.

Does the DTC reset?

--

Go to Step 2

System OK