Diagnostic procedure

WARNING: This page is about a different car, the 2005 Mazda MX-5 Miata. However, it is still accessible from the selected car via links, so may be relevant.

DTC P0506 [BP, BP WITH TC] 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 diagnostic 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 OR STORED DTCS Turn ignition key to OFF, then ON (Engine off). Verify pending code or stored DTCs using the WDS or equivalent. Is other DTC present?	Yes	Repair applicable DTCs. (See DTC TABLE )
3		No	Go to the next step.
4	INSPECT IAC VALVE MALFUNCTION Inspect IAC valve. (See IDLE AIR CONTROL (IAC) VALVE INSPECTION ) Is it normal?	Yes	Go to the next step.
4		No	Replace IAC valve, then go to Step 11.
5	INSPECT A/C MAGNET CLUTCH OPERATION Turn blower motor switch off. Is magnetic clutch still on?	Yes	Refer to "A/C is always on or A/C compressor runs continuously". of ENGINE SYMPTOM TROUBLESHOOTING, then go to Step 11. (See NO.24 A/C ALWAYS ON OR A/C COMPRESSOR RUNS CONTINUOUSLY [BP, BP WITH TC] )
5		No	Go to the next step.
6	INSPECT GENERATOR CONTROL CIRCUIT MALFUNCTION Turn the ignition switch off. Disconnect generator connector. Turn ignition key to ON. Measure voltage between generator terminal D (harness-side) and body GND. Is voltage 0 V ?	Yes	Go to the next step.
6		No	Repair short to power supply in generator control circuit, then go to Step 11.
7	INSPECT PURGE SOLENOID VALVE CONTROL MALFUNCTION Inspect purge solenoid valve. (See PURGE SOLENOID VALVE INSPECTION ) Is it normal?	Yes	Go to the next step.
7		No	Replace purge solenoid valve, then go to Step 11.
8	INSPECT ACL ELEMENT Remove ACL element with engine running. Is engine speed increased?	Yes	Replace ACL element, then go to Step 11.
8		No	Go to the next step.
9	INSPECT TB PASSAGE Is TB clogged?	Yes	Clean or replace TB passage, then go to Step 11.
9	INSPECT TB PASSAGE Is TB clogged?	No	Go to the next step.
10	INSPECT ENGINE COMPRESSION Inspect engine compression. (See COMPRESSION INSPECTION ) Is engine compression okay?	Yes	Go to the next step.
10		No	Overhaul engine, then go to the next step.
11	VERIFY TROUBLESHOOTING OF DTC P0506 COMPLETED Make sure to connect all disconnected connectors. Start engine. Clear the DTC from the PCM memory using the WDS or equivalent. Depress brake pedal for 14.1 s or more . Is same DTC present?	Yes	Replace PCM, then go to the next step.
11		No	Go to the next step.
12	VERIFY AFTER REPAIR PROCEDURE Perform the "AFTER REPAIR PROCEDURE ". (See AFTER REPAIR PROCEDURE ) Is any DTC present?	Yes	Go to the applicable DTC inspection. (See DTC TABLE )
12		No	Troubleshooting completed.