GM Service Manual Online
For 1990-2009 cars only

Circuit Description

The body control module (BCM) applies a ground through the brake pedal position sensor reference low circuit to the brake pedal position sensor. The BCM supplies a 10-volt reference through the brake sensor reference voltage circuit to the brake pedal position sensor. The brake pedal position sensor sends a variable voltage signal through the brake pedal position sensor signal circuit to the BCM as the brake pedal is applied.

DTC Descriptor

This diagnostic procedure supports the following DTC:

DTC C0278 Brake Pedal Position Sensor Not Calibrated

Conditions for Running the DTC

The battery voltage must be between 9-16 volts.

Conditions for Setting the DTC

DTC C0278 will set if the brake position sensor is out of calibration.

Action Taken When the DTC Sets

The stop lamps may not function correctly

Conditions for Clearing the DTC

    • This DTC will clear on current status after the condition for setting the fault is corrected.
    • A history DTC will clear after 100 consecutive ignition cycles with out a fault present.
    • History and current DTCs can be cleared using a scan tool.

Diagnostic Aids

    • If DTC C0278 sets then recalibrate the brake position sensor.
    •  Perform a visual inspection for a loose or poor connection at all related components. Refer to Testing for Intermittent Conditions and Poor Connections .

Step

Action

Yes

No

Schematic Reference: Exterior Lights Schematics

Connector End View Reference: Master Electrical Component List

1

Did you perform the Diagnostic System Check - Vehicle?

Go to Step 2

Go to Diagnostic System Check - Vehicle

2

  1. Install a scan tool.
  2. Turn ON the ignition, with the engine OFF.

Does the scan tool display DTC C0278?

Go to Step 3

Go to Testing for Intermittent Conditions and Poor Connections

3

Recalibrate the brake pedal position sensor. Refer to Brake Pedal Position Sensor Calibration .

Did you complete the repair?

Go to Step 4

--

4

  1. Install a scan tool.
  2. Turn ON the ignition, with the engine OFF.

Does the scan tool display DTC C0278?

Go to Step 5

Go to Step 6

5

Important: After replacing the brake pedal position sensor, perform the calibration procedure. Refer to Brake Pedal Position Sensor Calibration .

Replace the brake pedal position sensor. Refer to Brake Pedal Position Sensor Replacement .

Did you complete the replacement?

Go to Step 6

--

6

  1. Use the scan tool in order to clear the DTCs.
  2. Operate the vehicle within the Conditions for Running the DTC.

Does the DTC reset?

Go to Step 2

System OK