GM Service Manual Online
For 1990-2009 cars only

Object Number: 247754  Size: MF
ABS Components
Antilock Brake System Schematics
Handling Electrostatic Discharge Sensitive Parts Notice
OBDII Symbol Description Notice
Power Distribution Schematics
Exterior Lights Schematics

Circuit Description

DTC C1295 identifies open brake switch circuitry that prevents the brake switch input to the EBTCM from changing states while applying the brake. DTC C1295 is used in conjunction with DTC C1291 and DTC C1292 to determine the cause of an open brake switch malfunction.

Conditions for Setting the DTC

DTC C1295 can set after initialization is complete.

A malfunction exists if the brake switch input voltage is out of specification for one second. An open circuit exists when the brake switch input voltage is out of specification.

Action Taken When the DTC Sets

    • A malfunction DTC stores.
    • ABS/ETS disables.
    • The amber ABS/ETS warning indicators turns on.

Conditions for Clearing the DTC

    • The condition responsible for setting the DTC no longer exists and the Scan Tool Clear DTCs function is used.
    • 100 drive cycles pass with no DTCs detected.

Diagnostic Aids

If the malfunction is not current, use wiggle test on the wiring harness to pinpoint an intermittent malfunction in the motor circuitry or connections. Thoroughly inspect any circuitry that may be causing the intermittent complaint for the following conditions:

    • Backed out terminals
    • Improper mating
    • Improperly formed or damaged terminals
    • Poor terminal-to-wiring connections
    • Physical damage to the wiring harness
    • Rubbed-through wire insulation
    • A broken wire inside the insulation

Step

Action

Value(s)

Yes

No

1

Was the Diagnostic System Check performed?

--

Go to Step 2

Go to Diagnostic System Check - ABS

2

  1. Turn the ignition switch to the ON position.
  2. Do not start the engine.

  3. Install a scan tool.
  4. Select Data List on the scan tool.
  5. Select Brake Switch Position on the scan tool.

Does the scan tool indicate that the brake switch circuit is open?

--

Go to Step 3

Go to Step 11

3

Apply light pressure to the brake pedal while monitoring the Brake Switch Position on the scan tool.

Does the scan tool indicate that the brake switch is on within 25 mm (1.0 inch) of the brake pedal travel?

--

Go to Step 9

Go to Step 4

4

  1. Apply firm pressure to the brake pedal.
  2. Observe the rear brake lamps.

Are the rear brake lamps on?

--

Go to Step 5

Go to Step 9

5

  1. Turn the ignition switch to the OFF position.
  2. Disconnect the 24-way EBTCM connector C1.
  3. Turn the ignition switch to the ON position.
  4. Do not start the engine.

  5. Apply firm pressure to the brake pedal.
  6. Use the J 39200 in order to measure the voltage between the 24-way EBTCM connector C1 terminal B9 and ground.

Is the voltage equal to or greater than the specified voltage?

10.0 V

Go to Step 6

Go to Step 7

6

Inspect the 24-way EBTCM connector C1 and the 24-way EBTCM harness connector C1 for the following conditions:

    • Terminal damage
    • Poor terminal contact
    • Terminal corrosion

Are poor terminal contact, terminal corrosion or damaged terminals evident?

--

Go to Step 8

Go to Step 10

7

Repair the open in CKT 17.

Is the repair complete?

--

Go to Diagnostic System Check - ABS

--

8

Replace all the terminals or the connectors that exhibit the following conditions:

    • Poor terminal contact
    • Terminal corrosion
    • Damaged terminals.

Is the repair complete?

--

Go to Diagnostic System Check - ABS

--

9

Repair the open brake lamp circuit wiring.

Is the repair complete?

--

Go to Diagnostic System Check - ABS

--

10

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

Is the repair complete?

--

Go to Diagnostic System Check - ABS

--

11

Is the malfunction intermittent or is not present at this time?

--

Refer to Diagnostic Aids

--