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 10-volt reference through the brake sensor reference voltage circuit to the brake 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 9.0-16.0 volts.
Conditions for Setting the DTC
| • | A short to ground or an open in the brake pedal position sensor voltage reference circuit is present. |
| • | A short battery positive voltage in the brake pedal position sensor voltage reference circuit is present. |
Action Taken When the DTC Sets
The stop lamps will not function correctly.
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.
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 Lighting System Diagnostic System Check? | Go to Step 2 | |
2 |
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 |
Does the test light illuminate? | Go to Step 4 | Go to Step 5 |
4 | Test for a short to battery positive voltage in the brake pedal position sensor voltage reference circuit. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | Go to Step 11 | Go to Step 6 |
5 | Test for a short to ground on the brake pedal position sensor reference voltage circuit. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | Go to Step 11 | Go to Step 6 |
6 | 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 11 | Go to Step 7 |
7 |
Important: After replacing the brake pedal sensor, perform the calibration procedure. Refer to Brake Pedal Position Sensor Calibration Description and Operation . Replace the brake pedal position sensor. Refer to Brake Pedal Position Sensor Replacement . Did you complete the replacement? | Go to Step 8 | -- |
8 |
Does DTC C0870 reset? | Go to Step 9 | Go to Step 11 |
9 | 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 11 | Go to Step 10 |
10 |
Important: After replacing the BCM, perform the setup procedure. Refer to Body Control Module (BCM) Programming/RPO Configuration in Body Control System. Replace the body control module. Refer to Body Control Module Replacement in Body Control System. Did you complete the replacement? | Go to Step 11 | -- |
11 |
Does the DTC reset? | Go to Step 2 | System OK |
