GM Service Manual Online
For 1990-2009 cars only

Object Number: 95897  Size: MF
ABS Components
ABS/TCS Schematics

Circuit Description

This DTC is used to identify open Stoplamp Switch circuitry that prevents the Stoplamp Switch input to the EBTCM from changing states when the brake is applied.

This DTC is used in conjunction with DTC C1291 to determine the cause of an open Stoplamp Switch malfunction.

Conditions for Setting the DTC

DTC C1295 can be set after initialization is completed. If the Stoplamp Switch input voltage is out of specification for one second indicating an open circuit, a malfunction exists.

Action Taken When the DTC Sets

A malfunction DTC is stored, TCS is disabled and the 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.
    • Fifty ignition cycles have passed with no DTC(s) detected.

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.
    • If an intermittent malfunction exists refer to General Electrical Diagnosis in Wiring Systems.
    • Possible causes:
       - Stoplamp switch input circuit open.
       - All brake lamps open.
       - Stoplamp switch open or misadjusted.
       - Open brake lamp ground.
       - Circuit has a wiring problem, terminal corrosion, or poor connections.

Test Description

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

  1. Checks for voltage at EBTCM.

  2. Checks the Stoplamp Switch.

DTC C1295 Brake Lamp Switch Circuit Open

Step

Action

Value(s)

Yes

No

1

Was the Diagnostic System Check performed?

--

Go to Step 2

Go to Diagnostic System Check

2

Press the brake pedal.

Do the brake lights come on?

--

Go to Step 3

Go to Step 6

3

  1. Turn the ignition switch to the OFF position.
  2. Disconnect the EBTCM.
  3. Install J 39700 Universal Pinout Box using J 39700-25 adapter cable to the EBTCM harness connector only.
  4. Turn the ignition switch to the ON position, engine OFF.
  5. Using J 39200 DMM, measure the voltage at terminal 9 of J 39700 while an assistant presses the brake pedal.

Is the voltage within the range specified in the value(s) column?

Battery voltage

Go to Step 4

Go to Step 5

4

Replace the EBTCM. Refer to Electronic Brake and Traction Control Module .

Is the replacement complete?

--

Go to Diagnostic System Check

--

5

Repair open in CKT 20. Refer to Wiring Repairs in Wiring Systems.

--

Go to Diagnostic System Check

--

6

Check the STOP/HAZ fuse in the Instrument Panel Electrical Center.

Is the fuse OK?

--

Go to Step 7

Go to Step 11

7

  1. Disconnect the Stoplamp switch connector.
  2. Using the J 39200 DMM, measure the voltage at terminal A of the Stoplamp switch harness connector.

Is the voltage within the range specified in the value(s) column?

Battery voltage

Go to Step 9

Go to Step 8

8

Repair CKT 140 for an open. Refer to Wiring Repairs in Wiring Systems.

Is the repair complete?

--

Go to Diagnostic System Check

--

9

Connect a fused jumper wire between terminals A and B of the Stoplamp switch harness connector.

Do the brake lamps come on?

--

Go to Step 10

Go to Step 5

10

Adjust or repair the Stoplamp switch as necessary. Refer to Stop Lamp Switch Adjustment in Hydraulic Brakes.

Is the repair complete?

--

Go to Diagnostic System Check

--

11

  1. Replace the STOP/HAZ fuse. Do not press the brake pedal.
  2. Check the STOP/HAZ fuse.

Is the fuse OK?

--

Go to Step 13

Go to Step 12

12

Repair short to ground in CKT 140. Refer to Wiring Repairs in Wiring Systems.

Is the repair complete?

--

Go to Diagnostic System Check

--

13

  1. Press the brake pedal.
  2. Check the STOP/HAZ fuse.

Is the fuse OK?

--

Go to Diagnostic System Check

Go to Step 14

14

  1. Turn the ignition switch to the OFF position.
  2. Disconnect the EBTCM.
  3. Replace the fuse.
  4. Press the brake pedal.
  5. Check the STOP/HAZ fuse.

Is the fuse OK?

--

Go to Step 4

Go to Step 15

15

Repair CKT 20 for a short to ground. Refer to Wiring Repairs in Wiring Systems.

Is the repair complete?

--

Go to Diagnostic System Check

--