Safety Warning
DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.
DTC P0571
DTC P0571 : Brake Pedal Position Switch Circuit Malfunction
NOTE:
- Before you troubleshoot, review the general troubleshooting information .
- If the accelerator pedal is pressed while pressing the brake pedal lightly and continuously for 5 minutes or more, this DTC will be stored.
| DTC Description | Confirmed DTC | Pending DTC | Freeze Frame |
|---|---|---|---|
| P0571 Brake Pedal Position Switch Circuit Malfunction |
DTC (PGM-FI)
- Brake lights check 1
-1. Check the brake lights without the brake pedal pressed.
Do the brake lights stay on?
YES
Go to step 9.
NO
Go to step 2
- Brake lights check 2
-1. Check the brake lights with the brake pedal pressed.
Do the brake lights come on?
YES
Go to step 3.
NO
Go to step 5.
- Brake pedal position switch signal check
-1. Turn the vehicle to the ON mode.
-2. Check the parameter (s) below with the HDS.
Signal Current conditions Values Unit BRAKE SWITCH Does the signal change ON and OFF when the brake pedal is pressed and released?
YES
Intermittent failure, the system is OK at this time. Check for poor connections or loose terminals at the brake pedal position switch and the PCM. If the freeze data/on-board snapshot of this DTC is recorded, try to reproduce the failure under the same conditions with the freeze data/on-board snapshot .
NO
Go to step 4.
- Open wire check (BRK DIAG line)
-1. Turn the vehicle to the OFF (LOCK) mode.
-2. Jump the SCS line with the HDS.
-3. Disconnect the following connector.
PCM connector A (51P) -4. Press the brake pedal, and measure the voltage between test points 1 and 2.
Test condition Vehicle OFF (LOCK) mode PCM connector A (51P): disconnected Brake pedal pressed Test point 1 PCM connector A (51P) No. 13 Test point 2 Body ground Is there battery voltage?
YES
The BRK DIAG wire is OK. Update the PCM if it does not have the latest software, or substitute a known-good PCM , then recheck. If DTC P0571 goes away and the PCM was updated, troubleshooting is complete. If DTC P0571 goes away and the PCM was substituted, replace the original PCM .
NO
Repair an open in the BRK DIAG wire between the PCM (A13) and the brake pedal position switch.
- Brake pedal position switch check
-1. Test the brake pedal position switch .
Is the brake pedal position switch normal?
YES
Go to step 6.
NO
- Fuse check
-1. Check the following fuse.
Fuse No. B6 (10 A) Location Under-hood fuse/relay box Is the fuse OK?
YES
Go to step 7.
NO
Replace the No. B6 (10 A) fuse. Also check for a short to ground on the No. B6 (10 A) fuse circuit if needed.
- Open wire check (+B STOP line)
-1. Measure the voltage between test points 1 and 2.
Test condition Vehicle OFF (LOCK) mode Test point 1 Brake pedal position switch 4P connector No. 2 Test point 2 Body ground Is there battery voltage?
YES
The +B STOP wire is OK. Go to step 8.
NO
Repair an open in the +B STOP wire between the No. B6 (10 A) fuse in the under-hood fuse/relay box and the brake pedal position switch.
- Open wire check (BRK DIAG line)
-1. Jump the SCS line with the HDS.
-2. Disconnect the following connector.
PCM connector A (51P) -3. Press the brake pedal, and measure the voltage between test points 1 and 2.
Test condition Vehicle OFF (LOCK) mode PCM connector A (51P): disconnected Brake pedal pressed Test point 1 PCM connector A (51P) No. 13 Test point 2 Body ground Is there battery voltage?
YES
The BRK DIAG wire is OK. Update the PCM if it does not have the latest software, or substitute a known-good PCM , then recheck. If DTC P0571 goes away and the PCM was updated, troubleshooting is complete. If DTC P0571 goes away and the PCM was substituted, replace the original PCM .
NO
Repair an open in the BRK DIAG wire between the PCM (A13) and the brake pedal position switch.
- Brake pedal position switch installation check
-1. Remove the brake pedal position switch with the connector is connected .
-2. Check the brake lights with the rod of the brake pedal position switch pressed.
Do the brake lights go off?
YES
The brake pedal position switch is OK, install the brake pedal position switch and adjust the pedal height .
NO
Go to step 10.
- Brake pedal position switch check
-1. Test the brake pedal position switch .
Is the brake pedal position switch normal?
YES
The brake pedal position switch is OK, repair a short to power in the BRK DIAG wire between the PCM (A13) and the brake pedal position switch.
NO
NO RELATED
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When to See a Mechanic
Stop DIY work and contact a certified mechanic immediately if any of the following apply:
- • You smell fuel, burning insulation, or see smoke.
- • Brakes feel soft, pull hard to one side, or make grinding noises.
- • The engine overheats, stalls repeatedly, or misfires under load.
- • You are missing required tools, torque specs, or safe lifting equipment.
- • You are not confident in the next step or safety outcome.