Automatic Transmission - MVB 4 Speed
DTC P0724
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 Descriptor
DTC P0724
- Brake Switch B Circuit High
Diagnostic Fault Information
Circuit/System Description
The stop lamp switch input to the powertrain control module (PCM) is use for torque converter clutch (TCC) operation. The stop lamp switch is a normally open switch. When the brakes pedal is depressed, the switch sends a voltage signal to the PCM to cancel the TCC operation, while braking is in progress.
Conditions for Running the DTC
The engine is running.
Conditions for Setting the DTC
This DTC will set if the brake switch remains high between 3 km/h (2 mph) and 30 km/h (19 mph) for two driving cycles.
Action Taken When the DTC Sets
DTC P0724 is a type B DTC.
Conditions for Clearing the DTC
DTC P0724 is a type B DTC.
Diagnostic Aids
* The battery must be fully charged. Refer to Battery Inspection/Test (Battery Inspection/Test).
* All resistance tests are conducted with the component at 20°C (68°F).
Reference Information
Schematic Reference
Automatic Transmission Controls Schematics (Diagrams)
Connector End View Reference
Component Connector End Views (Connector Views)
Description and Operation
Mechanical Component Description (Mechanical Component Description)
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)
DTC Type Reference
Powertrain Diagnostic Trouble Code (DTC) Type Definitions (Powertrain Diagnostic Trouble Code (DTC) Type Definitions)
Scan Tool Reference
Powertrain Control Module Scan Tool Information (Scan Tool Testing and Procedures) for scan tool information.
Circuit/System Verification
1. Ignition ON, verify with a scan tool, the TCC brake pedal switch parameter changes from applied to release as the brake pedal is depressed and released.
2. Adjust the stop lamp switch. Refer to Stop Lamp Switch Adjustment (Adjustments).
3. Operate the vehicle within the conditions for running the DTC to verify the DTC does not reset. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records data.
Circuit/System Testing
1. Ignition ON, with the brake pedal depressed, verify that a test lamp illuminates by back probing the stop lamp switch connector terminal 1.
• If the test lamp fails to illuminate, test the stop lamp voltage circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the stop lamp switch.
2. Ignition OFF, disconnect the PCM X1 connector.
3. Ignition ON, with the brake pedal depressed, verify that a test lamp illuminates between connector X1 terminal 36 and ground.
• If the test lamp does not illuminate, test the stop lamp signal circuit for a short to ground or an open/high resistance circuit. If the circuit tests normal replace the PCM.
Component Testing
1. Ignition OFF, disconnect the stop lamp switch harness connector.
2. Test for less than 1 ohm between terminal 1 and 2 on the stop lamp switch with the brake pedal depressed.
• If greater than 1 ohm, replace the stop lamp switch.
3. Test for greater than 10k ohm between terminal 1 and 2 on the stop lamp switch with the brake pedal released.
• If less than the specified value, replace the stop lamp switch.
Repair Instructions
Perform the Diagnostic Repair Verification (Verification Tests) after completing the repair.
* Stop Lamp Switch Replacement (Service and Repair)
* Powertrain Control Module Replacement (Service and Repair)
* Powertrain Control Module Programming and Setup (Testing and Inspection)