GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Chevrolet 🢒 2005 🢒 Cobalt 🢒 Restraints 🢒 SIR 🢒 DTC C0161

Circuit Description

The electronic brake control module (EBCM) receives battery positive voltage on the stop lamp switch circuit when the brake pedal is applied. The EBCM uses the signal from the stop lamp switch signal to enhance the antilock braking system.

DTC Descriptor

This diagnostic procedure supports the following DTC:

DTC C0161 ABS/TCS Brake Switch Circuit

DTC Symptom

DTC Symptom Descriptor

04

Open Circuit

11

Above Maximum Threshold

12

Below Minimum Threshold

Conditions for Running the DTC

C0161 04

    • The ignition is ON.
    • The ignition voltage is greater than 8 volts.

C0161 11

    • The ignition is ON.
    • The vehicle speed is greater than 16 km/h (10 mph).
    • The ignition voltage is greater than 8 volts.

C0161 12

    • The ignition is ON.
    • The ignition voltage is greater than 8 volts.

Conditions for Setting the DTC

C0161 04

The EBCM detects an open in the brake switch signal circuit.

C0161 11

    • The brake pedal is sensed as applied.
    • The vehicle speed is greater than 40 km/h (25 mph).
    • The vehicles acceleration exceeds 8 km/h per second (5 mph per second).

C0161 12

    • Brake pedal is not applied.
    • Traction Control is not active.
    • The vehicle has reached speed greater than 24 km/h (14 mph).
    • The vehicles deceleration exceeds 11.5 km/h per second (7 mph per second).
    • Conditions for setting the DTC occur 3 times.

Action Taken When the DTC Sets

No systems are disabled and no warning indicators or messages will appear.

Diagnostic Aids

The DTC C0161 11 can be set if the vehicle has been driven with the brake applied during acceleration. Inspect for a poor or intermittent connection, refer to Testing for Intermittent Conditions and Poor Connections .

Test Description

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

  1. The EBCM sources 5 volts on the stop lamp switch signal circuit. This small voltage has a ground path through the stop lamp bulbs. This DTC sets if the stop lamp ground is open or all stop lamp bulbs are open.

    2.

  2. This DTC detects an open stop lamp switch signal circuit from the stop lamp side of the splice pack to the EBCM.

Step

Action

Yes

No

Connector End View Reference: Antilock Brake System Connector End Views or Lighting Systems Connector End Views

1

Did you perform the Diagnostic System Check - Vehicle?

Go to Step 2

Go to Diagnostic System Check - Vehicle

2

Check the stop lamps for proper operation. Refer to Symptoms - Lighting Systems .

Did you find and correct a fault condition in the stop lamps?

Go to Step 7

Go to Step 3

3
  1. With the scan tool, observe the Brake Switch Status parameter in the ABS data list.
  2. Press and release the brake pedal.

Does the Brake Switch Status parameter switch states?

Go to Diagnostic Aids

Go to Step 4

4

Test the brake switch signal circuit for an open or short to power. Refer to Circuit Testing and Wiring Repairs .

Did you find and correct the condition?

Go to Step 5

Go to Diagnostic Aids

5

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 .

Did you find and correct the condition?

Go to Step 7

Go to Step 6

6

Replace the EBCM. Refer to Control Module References for replacement, setup, and programming.

Did you complete the repair?

Go to Step 7

--

7
  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