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DTC P0571

BHE010200500W05

DTC P0571 | Brake switch input circuit problem
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DETECTION CONDITION | • The PCM monitors the input signal from brake switch No.1 and brake switch No.2 when the engine is running. If the both input signals remain on or off, the PCM determines that there is a brake switch input circuit problem. Diagnostic support note • This is a continuous monitor (Other). • The MIL does not illuminate. • PENDING CODE is available if the PCM detects the above malfunction condition. • FREEZE FRAME DATA is available. • The DTC is stored in the PCM memory.
POSSIBLE CAUSE | • Brake switch malfunction • DSC HU/CM malfunction • Open circuit in wiring harness between battery positive terminal and brake switch terminal B • Short to GND in wiring harness between battery positive terminal and brake switch terminal B • Open circuit in wiring harness between brake switch terminal D and DSC HU/CM terminal AD • Short to power supply in wiring harness between brake switch terminal D and DSC HU/CM terminal AD • Short to GND in wiring harness between brake switch terminal D and DSC HU/CM terminal AD • PCM malfunction

Diagnostic procedure

STEP | INSPECTION | ACTION
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1 | VERIFY FREEZE FRAME DATA HAS BEEN RECORDED • Has FREEZE FRAME DATA been recorded? | Yes | Go to the next step.
No | Record the FREEZE FRAME DATA on the repair order, then go to the next step.
2 | VERIFY RELATED REPAIR INFORMATION AVAILABILITY • Verify related service repair information availability. • Is any related repair information available? | Yes | Perform repair or diagnosis according to the available repair information. • If the vehicle is not repaired, go to the next step.
No | Go to the next step.
3 | VERIFY RELATED PENDING CODE OR STORED DTC • Turn the ignition switch off, then to the ON position (Engine off). • Verify the related PENDING CODE or stored DTCs. • Are other DTCs present? | Yes | Go to the appropriate DTC inspection. (See DTC TABLE.)
No | Go to the next step.
4 | INSPECT BRAKE SWITCH CONNECTOR FOR POOR CONNECTION • Turn the ignition switch off. • Disconnect the brake switch connector. • Inspect for poor connection (such as damaged/pulled-out pins, corrosion). • Is there any malfunction? | Yes | Repair or replace the terminal, then go to Step 11.
No | Go to the next step.
5 | INSPECT BRAKE SWITCH NO.1 POWER CIRCUIT FOR OPEN CIRCUIT OR SHORT TO GND • Turn the ignition switch to the ON position (Engine off). • Measure the voltage between brake switch terminal B (wiring harness-side) and body GND. • Is the voltage B+? | Yes | Go to the next step.
No | Repair or replace the wiring harness for a possible open circuit or short to GND, then go to Step 11.
6 | INSPECT BRAKE SWITCH NO.1 SIGNAL CIRCUIT FOR SHORT TO GND • Turn the ignition switch off. • Inspect for continuity between brake switch terminal D (wiring harness-side) and body GND. • Is there continuity? | Yes | Repair or replace the wiring harness for a possible short to GND, then go to Step 11.
No | Go to the next step.
7 | INSPECT BRAKE SWITCH NO.1 SIGNAL CIRCUIT FOR SHORT TO POWER SUPPLY • Turn the ignition switch to the ON position (Engine off). • Measure the voltage between brake switch terminal D (wiring harness-side) and body GND. • Is the voltage B+? | Yes | Repair or replace the wiring harness for a possible short to power supply, then go to Step 11.
No | Go to the next step.
8 | INSPECT BRAKE SWITCH NO.1 • Inspect the brake switch No.1. (See BRAKE SWITCH INSPECTION.) • Is there any malfunction? | Yes | Replace the brake switch, then go to Step 11. (See BRAKE PEDAL REMOVAL/INSTALLATION.)
No | Go to the next step.
9 | INSPECT DSC HU/CM CONNECTOR FOR POOR CONNECTION • Turn the ignition switch off. • Disconnect the DSC HU/CM connector. • Inspect for poor connection (such as damaged/pulled-out pins, corrosion). • Is there any malfunction? | Yes | Repair or replace the terminal, then go to Step 11.
No | Go to the next step.
10 | INSPECT BRAKE SWITCH NO.1 SIGNAL CIRCUIT FOR OPEN CIRCUIT • Turn the ignition switch off. • Inspect for continuity between brake switch terminal D (wiring harness-side) and DSC HU/CM terminal AD (wiring harness-side). • Is there continuity? | Yes | Go to the next step.
No | Repair or replace the wiring harness for a possible open circuit, then go to the next step.
11 | VERIFY TROUBLESHOOTING OF DTC P0571 COMPLETED • Make sure to reconnect all disconnected connectors. • Clear the DTC from the PCM memory using the WDS or equivalent. • Start the engine. • Operate the brake pedal. • Is the same DTC present? | Yes | Replace the PCM, then go to the next step. (See PCM REMOVAL/INSTALLATION.)
No | Go to the next step.
12 | VERIFY AFTER REPAIR PROCEDURE • Perform the "AFTER REPAIR PROCEDURE". (See AFTER REPAIR PROCEDURE.) • Are any DTCs present? | Yes | Go to the applicable DTC inspection. (See DTC TABLE.)
No | DTC troubleshooting completed.