GM Service Manual Online
For 1990-2009 cars only

Object Number: 585716  Size: MF
ABS Components
Antilock Brake System Schematics
Power Distribution Schematics
Cruise Control Schematics
Exterior Lights Schematics
Handling Electrostatic Discharge Sensitive Parts Notice

Circuit Description

The EBCM sources 5 volts on the stoplamp signal circuit. The voltage is supplied a ground path through the stoplamp bulbs. This DTC sets when the path to ground is open or has high resistance.

Conditions for Running the DTC

This DTC can set at anytime that the EBCM is powered.

Conditions for Setting the DTC

    • The stoplamp switch signal voltage is between 2.2  volts and 5.0 volts.
    • The above condition is present for greater than 2.0 seconds.

Action Taken When the DTC Sets

    • 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 input circuit open.
       - All stoplamps open.
       - Open stoplamp ground.
       - Circuit has a wiring problem, terminal corrosion, or poor connections.
    • 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 Testing for Intermittent Conditions and Poor Connections in Wiring Systems.

Test Description

The number(s) below refer to the step number(s) on the diagnostic table.

  1. This DTC detects an open stop lamp signal circuit from the stoplamp side of the IP Accessory Wiring Junction Block to the EBCM.

  2. The EBCM sources 5 volts on the stoplamp signal circuit. This small voltage has a ground path through the stoplamp bulbs. This DTC sets if the path to ground is open.

DTC C1295 Brake Lamp Switch Circuit Open

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

  1. Press the brake pedal.
  2. With the scan tool, observe the Brake Switch Status parameter in the ABS data list.

Does the Brake Switch Status parameter display Applied?

--

Go to Step 4

Go to Step 3

3

Test the signal circuit of the stoplamp switch for an open. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 9

Go to Step 7

4

Press the brake pedal.

Are all of the stoplamps OFF?

--

Go to Step 5

Go to Diagnostic Aids

5

Test the feed circuit of the stoplamps for an open or high resistance.

Did you find and correct the condition?

--

Go to Step 9

Go to Step 6

6

Test the ground circuit for the stoplamps for an open or high resistance.

Did you find and correct the condition?

--

Go to Step 9

Go to Diagnostic Aids

7

Inspect for poor connections at the harness connector of the EBCM. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 9

Go to Step 8

8

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

Did you complete the replacement?

--

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