2010 Cadillac CTS Sedan AWD V6-3.6L Page 768
C0277 4B
The brake pedal position sensor home position is not learned.
Actions Taken When the DTC Sets
* The Service Brake Assist 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 (See: Diagrams/Electrical Diagrams/Lighting and Horns/System Diagram/Exterior Lights Schematics)
Connector End View Reference
Component Connector End Views (See: Diagrams/Connector Views)
Description and Operation
Exterior Lighting Systems Description and Operation (See: Lighting and Horns/Description and Operation/Exterior Lighting Systems Description
and Operation)
Electrical Information Reference
* Circuit Testing (See: Testing and Inspection/Component Tests and General Diagnostics/Circuit Testing/Circuit Testing)
* Connector Repairs (See: Testing and Inspection/Component Tests and General Diagnostics/Connector Repairs/Connector Repairs)
* Testing for Intermittent Conditions and Poor Connections (See: Testing and Inspection/Component Tests and General Diagnostics/Circuit
Testing/Testing for Intermittent Conditions and Poor Connections)
* Wiring Repairs (See: Testing and Inspection/Component Tests and General Diagnostics/Wiring Repairs/Wiring Repairs)
Scan Tool Reference
Control Module References (See: Testing and Inspection/Programming and Relearning) for scan tool information
Circuit/System Testing
C0277 06 and C0277 07, C0890 03, and C0890 07
1. Ignition OFF, disconnect the harness connector at the brake pedal position sensor.
2. Ignition OFF, verify that a test lamp illuminates between B+ and the low reference circuit terminals listed below:
* Terminal A (LHD)
* Terminal C (RHD)
瀚慖f 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 V between the 5 V reference circuit terminals listed below and ground:
* Terminal C (LHD)
* Terminal A (RHD)
瀚慖f less than the specified range, test the 5 V reference circuit for a short to ground or an open/high resistance. If the circuit tests normal,
replace the BCM.
瀚慖f greater than the specified range, test the 5 V 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 100 counts.
瀚慖f 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 the signal circuit terminal B and the 5 V reference circuit terminals listed below. Verify the scan tool
BPP Sensor parameter is greater than 400 counts.
