Diagnostic procedure

WARNING: This page is about a different car, the 2005 Mazda 6. However, it is still accessible from the selected car via links, so may be relevant.

DTC P0550 [AJ] 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 FREEZE FRAME DATA on repair order, then go to the next step.
2	VERIFY RELATED REPAIR INFORMATION AVAILABILITY Check for related Service Bulletins and/or online 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	INSPECT PSP SWITCH CONNECTOR FOR POOR CONNECTION Turn the ignition switch off. Disconnect PSP switch connector. Check for poor connection (such as damaged, pulled-out pins, and corrosion, etc.). Is there any malfunction?	Yes	Repair or replace the terminal, then go to Step 7.
3		No	Go to the next step.
4	INSPECT PSP SWITCH SIGNAL CIRCUIT FOR SHORT TO GND Turn the ignition switch off. Check continuity between PSP switch terminal A (harness-side) and body GND. Is there continuity?	Yes	Repair or replace harness for short to GND, then go to Step 7.
4		No	Go to the next step.
5	INSPECT PSP SWITCH Inspect PSP switch. (See POWER STEERING PRESSURE (PSP) SWITCH INSPECTION .) Is there any malfunction?	Yes	Replace PSP switch, then go to Step 7. (See POWER STEERING OIL PUMP DISASSEMBLY/ASSEMBLY [AJ] .)
5		No	Go to the next step.
6	INSPECT PCM CONNECTOR FOR POOR CONNECTION Turn the ignition switch off. Disconnect PCM connector. Check for poor connection (such as damaged, pulled-out pins, and corrosion). Is there any malfunction?	Yes	Repair or replace the terminal, then go to the next step.
6		No	Go to the next step.
7	VERIFY TROUBLESHOOTING OF DTC P0550 COMPLETED Make sure to reconnect all disconnected connectors. Start engine. Clear the DTC from the PCM memory using the WDS or equivalent. Drive vehicle 60.2 km/h {37.4 mph} or above for 1 min. Verify that ECT PID 60 °C {140 °F} or above using the WDS or equivalent. Is PENDING CODE same as DTC present?	Yes	Replace PCM, then go to the next step. (See PCM REMOVAL/INSTALLATION .)
7		No	Go to the next step.
8	VERIFY AFTER REPAIR PROCEDURE Perform "AFTER REPAIR PROCEDURE". (See AFTER REPAIR PROCEDURE .) Are any DTCs present?	Yes	Go to the applicable DTC inspection. (See DTC TABLE .)
8		No	Troubleshooting completed.