Diagnostic procedure

WARNING: This page is about a different car, the 2009 Mazda 6. However, it is still accessible from the selected car via links, so may be relevant.

STEP	INSPECTION	RESULTS	ACTION
1	Does the engine idle roughly?	Yes	Go to symptom troubleshooting "No 8 Engine runs rough/rolling idle" (See NO. 8 ENGINE RUNS ROUGH/ROLLING IDLE [MZI-3.7] .)
1	Does the engine idle roughly?	No	Go to the next step
2	Turn off the A/C switch and fan switch Does the A/C magnetic clutch engage?	Yes	Go to symptom troubleshooting "NO. 24 A/C IS ALWAYS ON OR A/C COMPRESSOR RUNS CONTINUOUSLY [L5] " (See NO. 24 A/C IS ALWAYS ON OR A/C COMPRESSOR RUNS CONTINUOUSLY [MZI-3.7] .)
2		No	Go to the next step
3	Verify the following Proper routing of and no damage to vacuum lines No air leakage from intake-air system Are all items normal?	Yes	Go to the next step
3		No	Service if necessary Repeat Step 3
4	Connect the M-MDS to the DLC-2 Switch ignition to ON (Engine off) Retrieve any DTCs Are there any DTCs displayed?	Yes	DTC is displayed: Go to the appropriate DTC inspection (See DTC TABLE [MZI-3.7] .)
4		No	No DTC is displayed: Go to the next step
5	Perform the electronic throttle control system operation inspection (See ENGINE CONTROL SYSTEM OPERATION INSPECTION [MZI-3.7] .) Does the electronic throttle control system function properly?	Yes	Go to the next step
5		No	Repair or replace the malfunctioning part according to electronic throttle control system operation inspection results
6	Disconnect the vacuum hose between the purge solenoid valve and the intake manifold from purge solenoid valve side Plug opening end of vacuum hose Drive the vehicle Does the engine condition improve?	Yes	Inspect the evaporative emission control system.
6		No	Go to the next step
7	Connect the M-MDS to the DLC-2 Access APP1, APP2, TP1, TP2, MAF and VSS PIDs Monitor each PID while driving vehicle (See PCM INSPECTION [MZI-3.7] .) Are PIDs normal?	Yes	Go to the next step
7		No	APP1, APP2 PIDS: Inspect the accelerator pedal position sensor. TP1, TP2 PID: Inspect TP sensor MAF PID: Inspect MAF sensor VSS PID: Inspect VSS
8	Access and monitor PCM PID BOO, TCM PID TR. Are PIDs values normal? (See PCM INSPECTION [MZI-3.7] .) (See ON-BOARD DIAGNOSTIC SYSTEM PID/DATA MONITOR INSPECTION [AW6A-EL] .)	Yes	Go to the next step.
8		No	If the BOO PID is not normal: Inspect brake switch, and related wiring harness for vibration or intermittent open/short circuit. If the TR PID is not normal: Replace TR switch
9	Verify test results. If normal, return to diagnostic index to service any additional symptoms. (See SYMPTOM DIAGNOSTIC INDEX [MZI-3.7] .) If malfunction remains, inspect related Service Bulletins and/or On-line Repair Information and perform repair or diagnosis. If vehicle is repaired, troubleshooting completed. If vehicle is not repaired or additional diagnostic information is not available, reprogram the PCM if a later calibration is available. Retest.