Diagnostic procedure

WARNING: This page is about a different car, the 2005 Mazda RX-8. However, it is still accessible from the selected car via links, so may be relevant.

DTC P0571 DIAGNOSTIC PROCEDURE

STEP	INSPECTION		ACTION
1	VERIFY FREEZE FRAME DATA HAS BEEN RECORDED Has FREEZE FRAME DATA been recorded?	Yes	Go to the next step.
1		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 Bulletins and/or on-line 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.
2		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 .)
3		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.
4		No	Go to the next step.
5	INSPECT BRAKE SWITCH NO.1 POWER CIRCUIT FOR OPEN CIRCUIT OR SHORT TO GROUND Turn the ignition switch to the ON position (Engine off). Measure the voltage between brake switch terminal B (wiring harness-side) and body ground. Is the voltage B+ ?	Yes	Go to the next step.
5		No	Repair or replace the wiring harness for a possible open circuit or short to ground, then go to Step 11.
6	INSPECT BRAKE SWITCH NO.1 SIGNAL CIRCUIT FOR SHORT TO GROUND Turn the ignition switch off. Inspect for continuity between brake switch terminal D (wiring harness-side) and body ground. Is there continuity?	Yes	Repair or replace the wiring harness for a possible short to ground, then go to Step 11.
6		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 ground. Is the voltage B+ ?	Yes	Repair or replace the wiring harness for a possible short to power supply, then go to Step 11.
7		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 .)
8		No	Go to the next step.
9	INSPECT ABS HU/CM OR DSC HU/CM CONNECTOR FOR POOR CONNECTION Turn the ignition switch off. Disconnect the ABS HU/CM or 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.
9		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 the following circuits: For ABS HU/CM models: brake switch terminal D (wiring harness-side) and ABS HU/CM terminal Y (wiring harness-side) For DSC HU/CM models: 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.
10		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 .)
11		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 .)
12		No	DTC troubleshooting completed.