AF40-6 (MDK) - Automatic Transmission
DTC P057B-P057D
Diagnostic Instructions
* Perform the Diagnostic System Check - Vehicle Diagnostic System Check - Vehicle prior to using this diagnostic procedure.
* Review Strategy Based Diagnosis Strategy Based Diagnosis for an overview of the diagnostic approach.
* Diagnostic Procedure Instructions Diagnostic Procedure Instructions provides an overview of each diagnostic category.
DTC Descriptors
DTC P057B
- Brake Pedal Position Sensor Performance
DTC P057C
- Brake Pedal Position Sensor Circuit Low Voltage
DTC P057D
- Brake Pedal Position Sensor Circuit High Voltage
Diagnostic Fault Information
Typical Scan Tool Data
Circuit/System Description
The body control module (BCM) monitors the brake pedal position (BPP) sensor. When the brake pedal is applied, the BCM detects a predetermined voltage signal. The BCM sends a serial data message to the transmission control module (TCM).
Conditions for Running the DTC
P057B, P057C and P057D
Ignition voltage is greater than 10 V.
Conditions for Setting the DTC
P057B
The TCM receives an invalid brake pedal status serial data message from the BCM
P057C
BPP sensor voltage is less than 0.25 V for 1 s.
P057D
BPP sensor voltage is greater than 4.75 V for 1 s.
Action Taken When the DTC Sets
DTCs P057B, P057C and P057D are Type B DTCs.
Conditions for Clearing the DTC
DTCs P057B, P057C and P057D are Type B DTCs.
Reference Information
Schematic Reference
Automatic Transmission Controls Schematics AF40-6 (MDK) - Automatic Transmission
Exterior Lights Schematics Exterior Lights Schematics
Connector End View Reference
Component Connector End Views Sunshade - Left
Electrical Information Reference
* Circuit Testing Circuit Testing
* Connector Repairs Connector Repairs
* Testing for Intermittent Conditions and Poor Connections Testing for Intermittent Conditions and Poor Connections
* Wiring Repairs Wiring Repairs
Description and Operation
Transmission Component and System Description Transmission Component and System Description
DTC Type Reference
Powertrain Diagnostic Trouble Code (DTC) Type Definitions Powertrain Diagnostic Trouble Code (DTC) Type Definitions
Scan Tool Reference
Control Module References Control Module References for scan tool information
Circuit/System Verification
1. Ignition ON, transmission in park (P), brake pedal released.
2. Verify with a scan tool the Pedal Position Sensor parameter in the Automatic Transmission Data list displays greater than 0.25 V.
• If 0.25 V or less
Refer to Circuit/System Testing.
• If greater than 0.25 V
3. Verify with a scan tool the Brake Pedal Position Sensor parameter changes as the brake pedal is applied and displays less than 4.75 V when the brake pedal is fully applied.
• If 4.75 V or greater, or the parameter does not change
Refer to Circuit/System Testing below.
• If less than 4.75 V and parameter changes
4. Verify with a scan tool the Brake Pedal Position Sensor Learned Release Position parameter is within 0.1 V of the Brake Pedal Position Sensor parameter when the brake pedal is fully released.
• If the difference is greater than 0.1 V
Perform the Brake Pedal Position Sensor Calibration Testing and Inspection with a scan tool.
• If the difference is 0.1 V or less
5. Operate the vehicle within the Conditions for Running the DTC. It may be helpful to operate the vehicle within the conditions identified from the Freeze Frame/Failure Records data.
6. Verify the DTC does not set.
• If the DTC is set
Refer to Circuit/System Testing below.
• If the DTC is not set
7. All OK.
Circuit/System Testing
Note: Circuit/System Verification must be performed before Circuit/System Testing.
1. Ignition OFF and all vehicle systems OFF, disconnect the harness connector at the B22 Brake Pedal Position Sensor. It may take up to 2 min for all vehicle systems to power down.
2. Test for less than 10 ohms between the low reference circuit terminal 19 and ground.
• If 10 ohms or greater
1. Ignition OFF and all vehicle systems OFF, disconnect the X1 harness connector at the K9 Body Control Module.
2. Test for less than 2 ohms in the low reference circuit end to end.
• If 2 ohms or greater, repair the open/high resistance in the circuit.
• If less than 2 ohms, replace the K9 Body Control Module.
• If less than 10 ohms
3. Ignition ON.
4. Test for 4.8-5.2 V between the 5 V reference circuit terminal 13 and ground.
• If less than 4.8 V
1. Ignition OFF, disconnect the X2 harness connector at the K9 Body Control Module.
2. Test for infinite resistance between the 5 V reference circuit and ground.
• If less than infinite resistance, repair the short to ground on the circuit.
• If infinite resistance.
3. Test for less than 2 ohms in the 5 V reference circuit end to end.
• If 2 ohms or greater, repair the open/high resistance in the circuit.
• If less than 2 ohms, replace the K9 Body Control Module.
• If greater than 5.2 V
1. Ignition OFF, disconnect the X2 harness connector at the K9 Body Control Module.
2. Test for less than 1 V between the 5 V reference circuit and ground.
• If 1 V or greater, repair the short to voltage on the circuit.
• If less than 1 V, replace the K9 Body Control Module.
• If between 4.8-5.2 V
5. Verify the scan tool Brake Pedal Position Sensor parameter is less than 0.25 V.
• If the parameter 0.25 V or greater
1. Ignition OFF, disconnect the X2 harness connector at the K9 Body Control Module, ignition ON.
2. Test for less than 0.25 V between the signal circuit terminal 7 and ground.
• If 0.25 V or greater, repair the short to voltage on the circuit.
• If less than 0.25 V, replace the K9 Body Control Module.
• If less than 0.25 V
6. Install a 3 A fused jumper wire between the signal circuit terminal 7 and the 5 V reference circuit terminal 13.
7. Verify the scan tool Brake Pedal Position Sensor parameter is 4.8 V or greater.
• If less than 4.8 V
1. Ignition OFF, disconnect the X2 harness connector at the K9 Body Control Module.
2. Test for infinite resistance between the signal circuit terminal 7 and ground.
• If less than infinite resistance, repair the short to ground on the circuit.
• If infinite resistance.
3. Test for less than 2 ohms in the signal circuit end to end.
• If 2 ohms or greater, repair the open/high resistance in the circuit.
• If less than 2 ohms, replace the K9 Body Control Module.
• If 4.8 V or greater
8. Test or replace the B22 Brake Pedal Position Sensor.
Repair Instructions
Perform the Diagnostic Repair Verification Verification Tests after completing the repair.
* Refer to Control Module References Control Module References for BCM replacement, programming and setup.
* Brake pedal position sensor replacement, refer to Brake Pedal Position Sensor Replacement Service and Repair.
* Perform the Brake Pedal Position Sensor Calibration Testing and Inspection.