For 1990-2009 cars

### Diagnostic Instructions

• | Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure.

• | Review Strategy Based Diagnosis for an overview of the diagnostic approach.

• | Diagnostic Procedure Instructions provides an overview of each diagnostic category.

### DTC Descriptors

DTC C0277 06: Brake Pedal Position Sensor Circuit Short to Ground or Open
DTC C0277 07: Brake Pedal Position Sensor Circuit Voltage Above Threshold
DTC C0277 09: Brake Pedal Position Sensor Circuit Rate of Change Above Threshold
DTC C0277 4B: Brake Pedal Position Sensor Calibration Not Learned
DTC C0890 03: Device Voltage Reference Output 3 Circuit Voltage Below Threshold
DTC C0890 07: Device Voltage Reference Output 3 Circuit Voltage Above Threshold

### Diagnostic Fault Information

Circuit | Short to Ground | Open/High Resistance | Short to Voltage | Signal Performance
--- | --- | --- | --- | ---
BCM B+ Terminal 4 X4 | B3445 00 | B3445 00 | -- | --
Brake Pedal Position Sensor 5-Volt Reference | C0277 06, C0890 03, C0161 71 | C0277 06, C0161 71 | C0277 07, C0161 71 | --
Brake Applied Signal Terminal 6 X5 | C0297 00, P0571 00 | 3 | 3 | --
Brake Pedal Position Sensor Signal | C0277 06, C0161 71 | C0277 06, C0161 71 | C0277 07, C0161 71 | C0277 09
Stop Lamp Control | B3445 00 | 1 | 1 | --
Brake Position Sensor Low Reference | -- | 1 | 1 | --
Center High Mounted Stop Lamp (CHMSL) Ground | -- | 2 | -- | --
Left Rear Tail/Stop Lamp Ground | -- | 1 | -- | --
Right Rear Tail/Stop Lamp Ground | -- | 1 | -- | --
1. Stop Lamps Malfunction 2. Center High Mounted Stop Lamp (CHMSL) Malfunction 3. Cruise Control Malfunction

### Circuit/System Description

The brake pedal position sensor is used to sense the action of the driver application of the brake pedal. The brake pedal position sensor provides an analog voltage signal that will increase as the brake pedal is applied. The body control module (BCM) provides a low reference signal and a 5-volt reference voltage to the brake pedal position sensor. When the variable signal reaches a voltage threshold indicating the brakes have been applied, the BCM will apply battery voltage to the stop lamp control circuit illuminating the left and right stop lamps and the center high mounted stop lamp (CHMSL). The BCM also applies battery voltage to the transmission control module (TCM) and engine control module (ECM) via the brake applied signal circuit.

### Conditions for Running the DTC

• | Battery voltage must be between 9-16 volts.

• | Brakes APPLIED.

### Conditions for Setting the DTC

DTC C0277 06 will set for the following conditions:

• | The BCM detects a short to ground or an open/high resistance in the brake pedal position sensor signal circuit.

• | The BCM detects a short to ground or an open/high resistance in the brake pedal position sensor 5-volt reference circuit.

DTC C0277 07 will set for the following conditions:

• | The BCM detects a short to battery voltage in the brake pedal position sensor signal circuit.

• | The BCM detects a short to battery voltage in the brake pedal position sensor 5-Volt Reference circuit.

#### C0277 09

The DTC will set when the BCM detects the brake pedal position sensor signal is changing faster than possible under normal operating conditions.

#### C0277 4B

The DTC will set when the brake pedal position sensor home position is not learned.

#### C0890 03

The DTC will set when the BCM detects a short to ground in the brake pedal position sensor voltage reference circuit for 0.5 seconds or greater.

#### C0890 07

The DTC will set when the BCM detects a short to battery voltage in the brake pedal position sensor voltage reference circuits for 0.5 seconds or greater.

### Actions Taken When the DTC Sets

• | The ABS Fault indicator is commanded ON.

• | If the DTC sets while the vehicle is running, the BCM will activate the brake lights when the vehicles transmission is not in the PARK position and the vehicle is not accelerating.

• | For DTC C0277 4B the stop lamps may not activate at the expected brake pedal positions.

### Conditions for Clearing the DTC

• | The condition responsible for setting the DTC no longer exists.

• | For DTC C0277 07 the ignition must be cycled before the code can be cleared.

• | For DTC C0277 4B a successful brake pedal position sensor calibration has been performed.

• | A history DTC will clear once 50 malfunction-free ignition cycles have occurred.

• | A DTC will not clear the current status until the next ignition cycle.

### Reference Information

#### Schematic Reference

Exterior Lights Schematics

#### Connector End View Reference

Component Connector End Views

#### Description and Operation

Exterior Lighting Systems Description and Operation

#### Electrical Information Reference

• | Circuit Testing

• | Connector Repairs

• | Testing for Intermittent Conditions and Poor Connections

• | Wiring Repairs

#### Scan Tool Reference

Control Module References for scan tool information

### Circuit/System Testing

#### C0277 06, C0277 07, C0890 03, and C0890 07

1. Ignition OFF, disconnect the harness connector at the brake pedal position sensor.
2. Ignition ON, verify that a test lamp illuminates between B+ and the low reference circuit terminal C.

⇒ | If the test lamp does not illuminate, test the low reference circuit for a short to voltage or an open/high resistance. If the circuit tests normal, replace the BCM.

3. Ignition ON, test for 4.8-5.2 volts between the 5-volt reference circuit terminal A and ground.

⇒ | If less than the specified range, test the 5-volt reference circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the BCM.

⇒ | If greater than the specified range, test the 5-volt reference circuit for a short to voltage. If the circuit tests normal, replace the BCM.

4. Verify the scan tool BPP Sensor parameter is less than 2 counts.

⇒ | If greater than the specified range, test the signal circuit terminal B for a short to voltage. If the circuit tests normal, replace the BCM.

5. Install a 3 A fused jumper wire between B+ and the signal circuit terminal B. Verify the scan tool BPP Sensor parameter is greater than 1000 counts.

⇒ | If less than the specified range, test the signal circuit for short to ground or an open/high resistance. If the circuit tests normal, replace the BCM.

6. If all circuits test normal, test or replace the brake pedal position sensor.

#### C0277 09

1. Replace the brake pedal position sensor.
2. Perform the brake pedal position sensor recalibration procedure. Refer to Brake Pedal Position Sensor Calibration.
3. Operate the vehicle within the Conditions for Running and Setting the DTC and verify the DTC does not reset.

⇒ | If the DTC resets, replace the BCM.

#### C0277 4B

Verify that DTC C0277 4B is not set.

⇒ | If the DTC is set, perform the brake pedal position sensor calibration procedure. If the DTC resets, replace the brake pedal position sensor.

### Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

• | Stop Lamp Switch Replacement

• | Brake Pedal Position Sensor Calibration

• | Control Module References for BCM replacement, setup, and programming