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 Descriptor
DTC C0870: Brake Pedal Position Sensor CircuitDiagnostic Fault Information
Circuit | Short to Ground | Open/High Resistance | Short to Voltage | Signal Performance |
|---|---|---|---|---|
10-Volt Reference | C0283, C0870 | C0277 | C0277, C0870 | -- |
Stop Lamp Switch Signal | C0283 | C0277 | C0277 | -- |
Low Reference | -- | C0277 | C0277 | -- |
Circuit/System Description
The body control module (BCM) provides a 10-volt reference voltage and a low reference signal to the brake pedal position sensor (BPPS). When the brake pedal is applied, the BPPS sends a variable voltage signal through the brake apply sensor signal circuit to the BCM. The voltage signal will increase as the brake pedal is further depressed. In response to this signal, the BCM applies battery positive voltage to the stop lamp switch signal circuit and the rear stop/turn lamp supply voltage circuits.
Conditions for Running the DTC
Ignition is ON
Conditions for Setting the DTC
The BCM detects an improper voltage on the 10-volt reference circuit
Action Taken When the DTC Sets
| • | The vehicle stop lamps will be inoperative |
| • | Cruise control operation will be disabled |
Conditions for Clearing the DTC
| • | The condition responsible for setting the DTC no longer exists |
| • | A history DTC will clear once 100 consecutive malfunction-free ignition cycles have occurred |
Reference Information
Schematic Reference
Connector End View Reference
Description and Operation
Exterior Lighting Systems Description and Operation
Electrical Information Reference
Scan Tool Reference
Control Module References for Scan Tool Information
Circuit/System Verification
Depress the brake pedal. The stop lamps should illuminate.
Circuit/System Testing
- Ignition OFF, disconnect the harness connector at the BPPS.
- Ignition ON, test for 9.8-10.2 volts between the 10-volt reference circuit terminal A and ground.
- If all circuits test normal, test or replace the BPPS.
| ⇒ | If greater than the specified range, test the 10-volt reference circuit for a short to voltage. If the circuit tests normal, replace the BCM. |
| ⇒ | If less than the specified range, test the 10-volt reference circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the BCM. |
Repair Instructions
Perform the Diagnostic Repair Verification after completing the diagnostic procedure.
| • | Control Module References for BCM replacement, setup, and programming |
