Diagnostic Instructions
DTC Descriptors
DTC P1575 00: Extended Travel Brake Switch Circuit
Circuit/System Description
Domestic
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 right and left stop lamp
control circuits, transmission control module (TCM), engine control module (ECM), and center high mounted stop lamp (CHMSL) control circuit.
Conditions for Running the DTC
Battery voltage must be between 9-16 volts.
Conditions for Setting the DTC
The DTC will set when the brake pedal position sensor home position is not learned.
Actions Taken When the DTC Sets
| • | The Service Vehicle Soon 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. |
Conditions for Clearing the DTC
| • | The condition responsible for setting the DTC no longer exists. |
| • | You issue a scan tool CLEAR DTCs command. |
| • | 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. |
Diagnostic Aids
Important: The stop lamps will not illuminate unless the ignition is in the ON position. For more detailed information concerning stop lamp operation, refer to
Exterior Lighting Systems Description and Operation .
C0277 09
If the DTC is set, replace the brake pedal position sensor. If the DTC resets, replace the BCM.
C0277 4B
If the DTC is set, recalibrate the brake pedal position sensor.
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
Scan Tool Reference
Control Module References
Circuit/System Testing
- Ignition OFF, disconnect the harness connector at the brake pedal position sensor.
- Ignition OFF, verify that a test lamp illuminates between B+ and the low reference circuit terminal B.
| ⇒ | If the test lamp does not illuminate, test the low reference circuit for an open/high resistance. |
- Ignition ON, test for 4.8-5.2 volts between the 5-volt reference circuit terminal C 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. |
- Verify the scan tool BPP sensor parameter is less than 2 counts.
| ⇒ | If greater than the specified range, test the signal circuit terminal A for a short to voltage. If the circuit tests normal, replace the BCM. |
- Install a 3A fused jumper wire between the signal circuit terminal A and the 5-volt reference circuit terminal C. 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. |
- If all circuits test normal, test or replace the brake pedal position sensor.
Repair Instructions
Perform the
Diagnostic Repair Verification after completing the diagnostic procedure.
