DTC C1294 Brake Lamp Switch Circuit Always Active. Buick Park Avenue 1999

For 1990-2009 cars only

Makes 🢒 Buick 🢒 1999 🢒 Park Avenue 🢒 DTC 🢒 DTC C1294 Brake Lamp Switch Circuit Always Active

ABS Components
Cell 44: Indicators and Stoplamp/BTSI Switch
Handling ESD Sensitive Parts Notice
Cell 110: Stoplamps
Cell 10: LP PK, Horn, HZDT/SG, Stop, PCM, Run/Crank, and R/PMP Fuses
Cell 110: Stoplamps
Cell 34: Stoplamp Switch

Circuit Description

This DTC occurs when the internal self-checking safety logic has determined that the stoplamp/BTSI switch is continuously on. The TCS cannot be activated when the stoplamp/BTSI switch is on.

Conditions for Setting the DTC

The DTC sets if the following occur:

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

•	The brake was never off during 2 consecutive drive cycles.

Action Taken When the DTC Sets

•	A malfunction DTC is stored.

•	The TCS is disabled.

•	The TRACTION CONTROL 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

•	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 can be caused by poor connections, broken insulation, or a wire that is broken inside the insulation.

•	If an intermittent malfunction exists, refer to Intermittents and Poor Connections Diagnosis in Wiring Systems.

•	This condition may be cause by the following:

-	A short to voltage in the stoplamp/BTSI switch circuit.

-	A misadjusted or shorted stoplamp/BTSI switch.

-	A pedal that is binding.

Test Description

The numbers below refer to the step numbers on the diagnostic table.

This step tests for a short to voltage.

Step

Action

Value(s)

Yes

Was the ABS Diagnostic System Check performed?

Go to Step 2

Go to Diagnostic System Check - ABS

Observe the rear brake lamps.

Are the rear brake lamps OFF?

Go to Step 4

Go to Step 3

Disconnect the stoplamp/BTSI switch connector.

Are the brake lamps ON?

Go to Step 6

Go to Step 7

Disconnect the EBCM/EBTCM harness connector.
Install the J 39700 universal pinout box using the J 39700-25 cable adapter to the EBCM/EBTCM harness connector only.
Using the J 39200 digital multimeter (DMM), measure the voltage between the J 39700 terminal 9 and ground.

Is the voltage greater than the specified value?

1.0 V

Go to Step 6

Go to Step 5

Turn the ignition switch to the OFF position.
Disconnect all of the connectors.
Inspect CKT 20 and the EBCM/EBTCM harness connector for damage which may result in a short to voltage.
Reconnect all of the connectors.
Drive the vehicle for 3 drive cycles. A drive cycle consists of the following actions:

5.1.	Starting the engine.

5.2.	Driving above 40 km/h (25 mph) and back to 0 km/h (0 mph).

5.3.	Turning the ignition switch to the OFF position.

Was DTC C1294 set in the last 3 drive cycles?

Go to Step 8

Go to Diagnostic System Check - ABS

Repair the short to voltage in CKT 20. Refer to Wiring Repairs in Wiring Systems.

Is the circuit repair complete?

Go to Diagnostic System Check - ABS

Adjust or replace the stoplamp/BTSI switch as needed. Refer to Stop Lamp Switch Replacement in Hydraulic Brakes.

Is the repair complete?

Go to Diagnostic System Check - ABS

Replace the EBCM/EBTCM. Refer to Electronic Brake Control Module Replacement .

Is the repair complete?

Go to Diagnostic System Check - ABS