GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Saturn 🢒 2005 🢒 RELAY 🢒 Restraints 🢒 SIR 🢒 DTC C0163-C0165

Circuit Description

The body control module (BCM) receives a signal from the brake pedal position (BPP) sensor. The BCM illuminates the stop lamps by applying battery positive voltage to the stop lamp supply voltage circuit. The electronic brake control module (EBCM) receives a voltage input from the stop lamp supply voltage circuit to determine if the brake pedal is applied.

DTC Descriptors

This diagnostic procedure supports the following DTCs:

    • DTC C0163 Antilock Brake System (ABS)/Traction Control System (TCS) Brake Switch/Sensor Circuit Low
    • DTC C0164 Antilock Brake System (ABS)/Traction Control System (TCS) Brake Switch/Sensor Circuit High
    • DTC C0165 Antilock Brake System (ABS)/Traction Control System (TCS) Brake Switch/Sensor Circuit Open

Conditions for Running the DTCs

C0163, C0164 or C0165

The ignition voltage is greater than 8 volts.

Conditions for Setting the DTC

C0163

The DTC sets when the EBCM detects that the vehicle decelerates without a brake apply signal. All of the conditions below must be met 2 times before the DTC sets:

    • The EBCM does not receive a voltage input from the stop lamp supply voltage circuit.
    • ABS, vehicle stability enhancement system (VSES), and Traction Control System (TCS) is not active.
    • Vehicle speed exceeds 24 km/h (15 mph) and decelerates greater than 12 km/h (7 mph) per second.
    • Vehicle speed drops below 24 km/h (15 mph) during deceleration.

C0164

The DTC sets when the EBCM detects that the vehicle accelerates with a brake apply signal. All of the conditions below must be met 2 times before the DTC sets:

    • The EBCM receives a voltage input from the stop lamp supply voltage circuit.
    • Vehicle speed exceeds 40 km/h (25 mph).
    • Vehicle acceleration exceeds 8 km/h (5 mph) per second.

C0165

The DTC sets when the EBCM detects an open in the stop lamp supply voltage circuit. The EBCM determines an open circuit if the voltage at the stop lamp supply voltage circuit is between 75 percent and 40 percent of ignition voltage.

Action Taken When the DTC Sets

If equipped, the following actions will occur:

    • The EBCM disables the VSES for the duration of the ignition cycle.
    • The EBCM disables the TCS for the duration of the ignition cycle.
    • The Traction Control Off indicator turns ON.
    • The driver information center (DIC) displays the Service Stability System and Service Traction System message.

Conditions for Clearing the DTC
    • The condition for the DTC is no longer present and the DTC is cleared with a scan tool.
    • The EBCM automatically clears the history DTC when a current DTC is not detected in 100 consecutive drive cycles.

Diagnostic Aids

The DTC C0164 can be set if the vehicle has been driven with the brake applied during acceleration.

Test Description

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

  1. Symptoms in the stop lamp circuit can cause the DTC to set.

  1. This step checks for a BPP DTC. BPP failure can cause the DTC to set.

    2.

  2. This step Checks to see if the DTC will reset as current.

Step

Action

Yes

No

Schematic Reference: Antilock Brake System Schematics

Connector End View Reference: Antilock Brake System Connector End Views and Computer/Integrating Systems Connector End Views in Computer/Integrating Systems

1

Did you perform the Diagnostic System Check - Vehicle?

Go to Step 2

Go to Diagnostic System Check - Vehicle in Vehicle DTC Information

2

Are the stop lamps always ON or one or more inoperative?

Go to Symptoms - Lighting Systems in Lighting Systems

Go to Step 3

3

Use the scan tool to display DTCs for the body control module (BCM).

Does the scan tool display DTC C0277 or C0278?

Go to Diagnostic Trouble Code (DTC) List - Vehicle in Vehicle DTC Information

Go to Step 4

4

Confirm that the brake pedal position (BPP) is adjusted to the correct position and perform the BPP calibration procedure. Refer to Brake Pedal Position Sensor Calibration in Lighting Systems.

Operate the vehicle within the Conditions for Running the DTC as specified in the supporting text.

Does the DTC reset?

Go to Step 5

Go to Step 6

5

Repair open or short in the center high mounted stop lamp (CHMSL) resistor.

Did you find and correct the condition?

Go to Step 6

Go to Step 2

6
  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