GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Chevrolet 🢒 2005 🢒 Vivant 🢒 Brakes 🢒 Antilock Brake System 🢒 DTC C0095

Circuit Description

This DTC is used to identify open stop lamp switch circuitry that prevents the stop lamp switch input to the electronic brake control module (EBCM) from changing states when the brake is applied. The EBCM sends a low current 5-volt sense voltage on brake switch input line to the rear brake light bulbs. If the rear brake light circuit is intact, this voltage will be pulled low, under 1 volt, to ground through the rear brake light bulbs. When the brake light switch is depressed, battery voltage will be supplied to the rear brake lights and to the EBCM, indicating the brake lights are ON. If the voltage is either low, under 1 volt, or high, battery voltage, the EBCM cannot determine the brake switch state and DTC C0095 will set.

Conditions for Setting the DTC

DTC C0095 can be set after initialization. If the voltage on the brake switch input line voltage is between 2-5 volts for 2 seconds, the DTC will set.

Action Taken When the DTC Sets

The antilock brake system (ABS) remains functional.

Conditions for Clearing the DTC
    • If the condition that set DTC 0095 is no longer present, the DTC may be cleared by using the proper scan tool.
    • The DTC that has not occurred in 100 drive cycles will be cleared from history data.

Diagnostic Aids

The following are typical causes of DTC C0095:

    • One or more stop lamp bulb filaments open
    • One or more stop lamp bulb and/or socket connections loose
    • One or more stop lamp grounds loose or open
    • Terminal C7 brake switch input terminal connection poor or open
    • Terminal C7 brake switch input circuit open

Step

Action

Values

Yes

No

1

Did you perform the Diagnostic System Check-ABS?

--

Go to Step 2

Go to Diagnostic System Check - ABS

2

Depress the brake pedal.

Are any brake light bulbs inoperative, including the CHMSL, 3rd, or center high brake light?

--

Go to Step 3

Go to Step 4

3
  1. Remove and inspect bulbs/sockets that do not illuminate when brake pedal is depressed.
  2. Replace bulbs/sockets/and repair grounds as necessary.

Did you find and correct the condition?

--

System OK

--

4
  1. Turn the ignition switch OFF.
  2. Disconnect the electronic brake control module (EBCM) harness from the EBCM.
  3. Install the universal breakout box inline between the EBCM and the EBCM harness using the applicable adapter cable.
  4. Connect a voltmeter to terminal C7 of the universal breakout box and then to either terminal C of the universal breakout box or to body ground.

Is the voltage less than the specified value?

2 V

Go to Step 6

Go to Step 5

5

Inspect all rear brake light grounds/bulbs/socks for poor connections/high resistance which would not allow the 5-volt reference signal from the EBCM to be pulled low, under 2 volts.

Did you find and correct the condition?

--

System OK

--

6

Replace the EBCM.

Did you complete the replacement?

--

System OK

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