DTC P0571 [L8, LF, L3]

DTC P0571	Brake switch circuit problem
DETECTION CONDITION	• The PCM monitors switching in conjunction with brake switches No.1 and No.2. If either No.1 or No.2 do not switch for a continuous five times even though either No.1 or No.2 is switched from off to on or from on to off, P0571 is detected. Diagnostic support note • This is a continuous monitor (Other). • MIL does not comes on. • PENDING CODE is available if PCM detects the above malfunction condition. • FREEZE FRAME DATA is not available. • DTC is stored in PCM memory.
POSSIBLE CAUSE	• Brake switch malfunction • Open circuit between brake switch terminal B and PCM terminal 1AF • Open circuit between brake switch terminal C and body ground • Short to power between brake switch terminal B and PCM terminal 1AF • Short to ground circuit between brake switch terminal B and PCM terminal 1AF • PCM malfunction

DTC P0571

Brake switch circuit problem

DETECTION CONDITION

• The PCM monitors switching in conjunction with brake switches No.1 and No.2. If either No.1 or No.2 do not switch for a continuous five times even though either No.1 or No.2 is switched from off to on or from on to off, P0571 is detected.

Diagnostic support note

• This is a continuous monitor (Other).

• MIL does not comes on.

• PENDING CODE is available if PCM detects the above malfunction condition.

• FREEZE FRAME DATA is not available.

• DTC is stored in PCM memory.

POSSIBLE CAUSE

• Brake switch malfunction

• Open circuit between brake switch terminal B and PCM terminal 1AF

• Open circuit between brake switch terminal C and body ground

• Short to power between brake switch terminal B and PCM terminal 1AF

• Short to ground circuit between brake switch terminal B and PCM terminal 1AF

• PCM malfunction

STEP	INSPECTION	ACTION
1	VERIFY FREEZE FRAME DATA AND DIAGNOSTIC MONITORING TEST RESULTS HAS BEEN RECORDED • Has FREEZE FRAME DATA been recorded?	Yes	Go to the next step.
No	Record the FREEZE FRAME on the repair order, then go to the next step.
2	VERIFY RELATED REPAIR INFORMATION AVAILABILITY • Verify related Service Information availability. • Is any related Service Information available?	Yes	Perform repair or diagnosis according to the available Service information. If the vehicle is not repaired, go to the next step.
No	Go to the next step.
3	VERIFY DTC FOR MODULE COMMUNICATION • Connect the WDS or equivalent to the DLC-2. • Turn the ignition switch to the ON position (Engine off). • Verify stored the DTC. • Is the DTC U0155 stored?	Yes	Go to the applicable DTC inspection. (See DTC TABLE [L8, LF, L3].)
No	Go to the next step.
4	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. • Is the DTC P0703 also present?	Yes	Go to the applicable DTC inspection. (See DTC TABLE [L8, LF, L3].)
No	Go to the next step.
5	INSPECT BRAKE SWITCH CONNECTOR FOR POOR CONNECTION • Turn the ignition switch off. • Disconnect the brake switch connector. • Inspect for poor connection (such as damaged, pull-out pins, corrosion). • Is there any malfunction?	Yes	Repair or replace the terminal, then go to Step 11.
No	Go to the next step.
6	INSPECT BRAKE SWITCH • Inspect the brake switch. • Is the brake switch normal?	Yes	Go to the next step.
No	Replace brake switch, then go to Step 11.
7	INSPECT GROUND CIRCUIT OF BRAKE SWITCH NO.2 FOR OPEN CIRCUIT • Inspect for continuity between brake switch terminal C (wiring harness-side) and body ground. • Is there continuity?	Yes	Go to the next step.
No	Repair or replace the wiring harness for an open circuit, then go to Step 11.
8	INSPECT SIGNAL CIRCUIT OF BRAKE SWITCH NO.2 FOR SHORT TO GROUND • Inspect for continuity between brake switch terminal B (wiring harness-side) and body ground. • Is there continuity?	Yes	Repair or replace the wiring harness for short to ground circuit, then go to Step 11.
No	Go to the next step.
9	INSPECT SIGNAL CIRCUIT OF BRAKE SWITCH NO.2 FOR OPEN CIRCUIT • Inspect for continuity between brake switch terminal B (wiring harness-side) and PCM terminal 1AF (wiring harness-side). • Is there continuity?	Yes	Go to the next step.
No	Repair or replace the wiring harness for an open circuit, then go to Step 11.
10	INSPECT SIGNAL CIRCUIT OF BRAKE SWITCH NO.2 FOR SHORT TO POWER • Turn the ignition switch to the ON position (Engine off). • Measure the voltage between brake switch terminal A (wiring harness-side) and body ground. • Is the voltage B+?	Yes	Repair or replace the wiring harness for short to power supply, then go to the next step.
No	Go to the next step.
11	VERIFY TROUBLESHOOTING OF P0571 COMPLETED • Make sure to reconnect all disconnected connectors. • Clear the DTC from the PCM memory using the WDS or equivalent. • Turn the ignition switch to the ON position (Engine off). • Depress and release the brake pedal more than 5 times. • Is the same DTC present?	Yes	Replace the PCM, then go to the next step. (See PCM REMOVAL/INSTALLATION [L8, LF, L3].)
No	Go to the next step.
12	VERIFY AFTER REPAIR PROCEDURE • Perform “AFTER REPAIR PROCEDURE”. (See AFTER REPAIR PROCEDURE [L8, LF, L3].) • Is any DTC present?	Yes	Go to the applicable DTC inspection. (See DTC TABLE [L8, LF, L3].)
No	Troubleshooting completed.

STEP

INSPECTION

ACTION

VERIFY FREEZE FRAME DATA AND DIAGNOSTIC MONITORING TEST RESULTS HAS BEEN RECORDED

• Has FREEZE FRAME DATA been recorded?

Yes

Go to the next step.

Record the FREEZE FRAME on the repair order, then go to the next step.

VERIFY RELATED REPAIR INFORMATION AVAILABILITY

• Verify related Service Information availability.

• Is any related Service Information available?

Yes

Perform repair or diagnosis according to the available Service information.

If the vehicle is not repaired, go to the next step.

Go to the next step.

VERIFY DTC FOR MODULE COMMUNICATION

• Connect the WDS or equivalent to the DLC-2.

• Turn the ignition switch to the ON position (Engine off).

• Verify stored the DTC.

• Is the DTC U0155 stored?

Yes

Go to the applicable DTC inspection.

(See DTC TABLE [L8, LF, L3].)

Go to the next step.

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.

• Is the DTC P0703 also present?

Yes

Go to the applicable DTC inspection.

(See DTC TABLE [L8, LF, L3].)

Go to the next step.

INSPECT BRAKE SWITCH CONNECTOR FOR POOR CONNECTION

• Turn the ignition switch off.

• Disconnect the brake switch connector.

• Inspect for poor connection (such as damaged, pull-out pins, corrosion).

• Is there any malfunction?

Yes

Repair or replace the terminal, then go to Step 11.

Go to the next step.

INSPECT BRAKE SWITCH

• Inspect the brake switch.

• Is the brake switch normal?

Yes

Go to the next step.

Replace brake switch, then go to Step 11.

INSPECT GROUND CIRCUIT OF BRAKE SWITCH NO.2 FOR OPEN CIRCUIT

• Inspect for continuity between brake switch terminal C (wiring harness-side) and body ground.

• Is there continuity?

Yes

Go to the next step.

Repair or replace the wiring harness for an open circuit, then go to Step 11.

INSPECT SIGNAL CIRCUIT OF BRAKE SWITCH NO.2 FOR SHORT TO GROUND

• Inspect for continuity between brake switch terminal B (wiring harness-side) and body ground.

• Is there continuity?

Yes

Repair or replace the wiring harness for short to ground circuit, then go to Step 11.

Go to the next step.

INSPECT SIGNAL CIRCUIT OF BRAKE SWITCH NO.2 FOR OPEN CIRCUIT

• Inspect for continuity between brake switch terminal B (wiring harness-side) and PCM terminal 1AF (wiring harness-side).

• Is there continuity?

Yes

Go to the next step.

Repair or replace the wiring harness for an open circuit, then go to Step 11.

INSPECT SIGNAL CIRCUIT OF BRAKE SWITCH NO.2 FOR SHORT TO POWER

• Turn the ignition switch to the ON position (Engine off).

• Measure the voltage between brake switch terminal A (wiring harness-side) and body ground.

• Is the voltage B+?

Yes

Repair or replace the wiring harness for short to power supply, then go to the next step.

Go to the next step.

VERIFY TROUBLESHOOTING OF P0571 COMPLETED

• Make sure to reconnect all disconnected connectors.

• Clear the DTC from the PCM memory using the WDS or equivalent.

• Turn the ignition switch to the ON position (Engine off).

• Depress and release the brake pedal more than 5 times.

• Is the same DTC present?

Yes

Replace the PCM, then go to the next step.

(See PCM REMOVAL/INSTALLATION [L8, LF, L3].)

Go to the next step.

VERIFY AFTER REPAIR PROCEDURE

• Perform “AFTER REPAIR PROCEDURE”.

(See AFTER REPAIR PROCEDURE [L8, LF, L3].)

• Is any DTC present?

Yes

Go to the applicable DTC inspection.

(See DTC TABLE [L8, LF, L3].)

Troubleshooting completed.

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