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 the 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, the battery voltage will 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 ABS remains functional.
Conditions for Clearing the DTC
| • | If the conditions that set DTC C0095 are 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 the history data. |
Diagnostic Aids
The following are typical causes of DTC C0095:
| • | One or more stop lamp bulb filaments are open. |
| • | One or more stop lamp bulb and/or socket connections are loose. |
| • | One or more stop lamp grounds are loose or open. |
| • | Terminal 33 brake switch input terminal connection is poor or open. |
| • | Terminal 33 brake switch input circuit is open. |
Step | Action | Yes | No |
|---|---|---|---|
1 | Did you perform the Diagnostic System Check - ABS? | Go to Step 2 | |
2 |
Does the Brake Switch Status parameter display Applied? | Go to Step 4 | Go to Step 3 |
3 | Test the signal circuit of the stop lamp 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 stop lamps OFF? | Go to Step 5 | Go to Diagnostic Aids |
5 | Test the feed circuit of the stop lamps for an open or high resistance. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | Go to Step 9 | Go to Step 6 |
6 | Test the ground circuit of the stop lamps for an open or high resistance. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. 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 electronic brake control module (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 Brake Pressure Modulator Valve Assembly Replacement . Did you complete the replacement? | Go to Step 9 | -- |
9 |
Does the DTC reset? | Go to Step 2 | System OK |
