GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Cadillac 🢒 2004 🢒 XLR 🢒 Vehicle Control Systems 🢒 Vehicle DTC Information 🢒 DTC C0277

Circuit Description

The body control module (BCM) applies a ground through the brake sensor reference low circuit to the brake pedal position sensor. The BCM supplies a 5-volt reference through the brake sensor reference voltage circuit to the brake pedal position sensor. When the brake pedal is being applied, the brake pedal position sensor then sends a variable voltage signal through the brake sensor signal circuit to the BCM.

Conditions for Running the DTC

The battery voltage must be between 9-16 volts.

Conditions for Setting the DTC
    • DTC C0277 06 A short to ground or an open in the brake position sensor circuit is present.
    • DTC C0277 07 A short battery positive voltage in the brake position sensor circuit or the brake position sensor low reference circuit is present.
    • DTC C0277 09 A malfunctioning brake pedal position sensor or BCM.

Action Taken When the DTC Sets

The Service Vehicle Soon indicator is commanded ON.

Conditions for Clearing the DTC
    • The 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 without a fault present.
    • A History or current DTC can be cleared using a scan tool.

Diagnostic Aids
    • Perform a visual inspection for loose or poor connections at all related components. Refer to Testing for Intermittent Conditions and Poor Connections in Wiring Systems.
    • If DTC C0277 09 is set, replace the brake pedal position sensor. If the DTC resets replace the BCM.

Step

Action

Yes

No

Schematic Reference: Exterior Lights Schematics

Connector End View Reference: Master Electrical Component List in Wiring Systems

1

Did you perform the Diagnostic System Check?

Go to Step 2

Go to Diagnostic System Check - Vehicle in Vehicle DTC Information

2
  1. Install a scan tool.
  2. Turn ON the ignition, with the engine OFF.
  3. With a scan tool, observe the brake pedal position sensor parameter in the data list for the body control module (BCM).
  4. Apply and release the brake pedal.

Does the scan tool display a change in the voltage ?

Go to Testing for Intermittent Conditions and Poor Connections in Wiring Systems

Go to Step 3

3

Is DTC C0277 09 present?

Go to Step 10

Go to Step 4

4

Is DTC C0277 07 present?

Go to Step 5

Go to Step 8

5
  1. Turn OFF the ignition.
  2. Disconnect the BCM harness connector C2.
  3. At the BCM harness connector C2, connect a test lamp between the brake sensor signal circuit and ground.

Does the test light illuminate?

Go to Step 6

Go to Step 12

6

Test for a short to battery positive voltage in the brake sensor signal circuit. Refer to Circuit Testing and to Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 14

Go to Step 7

7

Test for a short to battery positive voltage in the brake sensor low reference circuit. Refer to Circuit Testing and to Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 14

Go to Step 9

8

Test for a short to ground or an open on the brake sensor signal circuit. Refer to Circuit Testing and to Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 14

Go to Step 9

9

Inspect for a high resistance or a poor connection at the harness connector of the brake position sensor. 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 14

Go to Step 10

10

Important: Always recalibrate the brake pedal position sensor after replacing the brake position sensor.

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

Did you complete the repair?

Go to Step 11

--

11
  1. Install a scan tool.
  2. Turn ON the ignition, with the engine OFF.
  3. Apply and release the brake pedal.

Does DTC C0277 reset?

Go to Step 12

Go to Step 14

12

Inspect for a high resistance or a poor connection at the harness connector of the BCM. 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 14

Go to Step 13

13

Important: After replacing the BCM, perform the setup procedure. Refer to Body Control Module (BCM) Programming/RPO Configuration in Computer/Integrating Systems.

Replace the body control module. Refer to Body Control Module Replacement in Computer/Integrating Systems.

Did you complete the replacement?

Go to Step 14

--

14
  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