DTC Troubleshooting: P0571
DTC P0571: Brake Pedal Position Switch Circuit Malfunction
NOTE:
Before you troubleshoot, record all freeze data and any on-board snapshot, and review the general troubleshooting information.
If the brake pedal is pressed 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
      

1.
Brake lights check 1:

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
2.
Brake lights check 2:

Brake lights check 2
?1.
Check the brake lights with the brake pedal pressed.

Do the brake lights come on?

     
YES
     
     
     
The failure is duplicated. Go to step 3.
     
NO
     
     
     
Go to step 5.
3.
Brake pedal position switch signal check:

Brake pedal position switch signal check
?1.
Turn the ignition switch to ON (II), or press the engine start/stop button to select 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.?
     
NO
     
     
     
Go to step 4.
4.
Open wire check (STOP SW line):

Open wire check (STOP SW line)
?1.
Turn the ignition switch to LOCK (0), or press the engine start/stop button to select the OFF mode.

?2.
Jump the SCS line with the HDS.


?3.
Disconnect the following connector.

?4.
Measure the voltage between test points 1 and 2.
Test condition
IG LOCK (0) or OFF mode
Brake pedal pressed
Test circuit
STOP SW
Test point 1
PCM connector A (51P) No. 37 (LT GRN)
Test point 2
Body ground


Is there battery voltage?

     
YES
     
     
     
The STOP SW wire is OK. Update the PCM if it does not have the latest software, or substitute a known-good PCM, then do the repair verification.
     
NO
     
     
     
Repair an open in the STOP SW wire between the PCM (A37) and the brake pedal position switch, then do the repair verification.
5.
Brake pedal position switch test:

Brake pedal position switch test
?1.
Test the brake pedal position switch.

Is the brake pedal position switch normal?

     
YES
     
     
     
Go to step 6.
     
NO
     
     
     
Replace the brake pedal position switch, then do the repair verification.
6.
Fuse check:

Fuse check
?1.
Check the following fuse.
Fuse
No. A6 (10 A)
Location
Under-hood fuse/relay box

Is the fuse OK?

     
YES
     
     
     
Go to step 7.
     
NO
     
     
     
Replace the No. A6 (10 A) fuse in the under-hood fuse/relay box. Also check for a short to ground on the No. A6 (10 A) fuse circuit if needed, then do the repair verification.
7.
Open wire check (+B STOP line):

Open wire check (+B STOP line)
?1.
Measure the voltage between test points 1 and 2.
Test condition
IG LOCK (0) or OFF mode
Test circuit
+B STOP
Test point 1
Brake pedal position switch 4P connector No. 2 (PNK)
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. A6 (10 A) fuse and the brake pedal position switch, then do the repair verification.
8.
Open wire check (STOP SW line):

Open wire check (STOP SW line)
?1.
Jump the SCS line with the HDS.


?2.
Disconnect the following connector.

?3.
Measure the voltage between test points 1 and 2.
Test condition
IG LOCK (0) or OFF mode
Brake pedal pressed
Test circuit
STOP SW
Test point 1
PCM connector A (51P) No. 37 (LT GRN)
Test point 2
Body ground


Is there battery voltage?

     
YES
     
     
     
The STOP SW wire is OK. Update the PCM if it does not have the latest software, or substitute a known-good PCM, then do the repair verification.
     
NO
     
     
     
Repair an open in the STOP SW wire between the PCM (A37) and the brake pedal position switch, then do the repair verification.
9.
Brake pedal position switch function test:

Brake pedal position switch function test
?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, then do the repair verification.
     
NO
     
     
     
Go to step 10.
10.
Brake pedal position switch test:

Brake pedal position switch test
?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 STOP SW wire between the PCM (A37) and the brake pedal position switch, then do the repair verification.
     
NO
     
     
     
Replace the brake pedal position switch, then do the repair verification.
Repair verification:

?1.
Turn the ignition switch to LOCK (0), or press the engine start/stop button to select the OFF mode.

?2.
Reconnect all connectors.

?3.
Exit the SCS mode with the HDS.


?4.
Turn the ignition switch to ON (II), or press the engine start/stop button to select the ON mode.

?5.
Reset the PCM with the HDS.


?6.
Do the PCM idle learn procedure.

?7.
Turn the ignition switch to LOCK (0), or press the engine start/stop button to select the OFF mode.

?8.
Turn the ignition switch to ON (II), or press the engine start/stop button to select the ON mode.

?9.
Press the brake pedal several times.

?10.
Check for Pending or Confirmed DTCs with the HDS.
DTC Description
Confirmed DTC
Pending DTC
Freeze Frame
P0571 Brake Pedal Position Switch Circuit Malfunction
      


Is DTC P0571 indicated?

     
YES
     
     
     
Check for poor connections or loose terminals at the brake pedal position switch and the PCM. If the PCM was updated, substitute a known-good PCM, then recheck. If the PCM was substituted, go to step 2.
     
NO
     
     
     
Troubleshooting is complete. If the PCM was substituted, replace the original PCM. If any other Pending or Confirmed DTCs are indicated, go to the indicated DTC's troubleshooting.?