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.

NO. 11 ENGINE STALLS/QUITS, ENGINE RUNS ROUGH, MISSES DIAGNOSTIC PROCEDURE

STEP	INSPECTION	RESULTS	ACTION
1	Verify the following: Vacuum connection Air cleaner element No air leakage from intake-air system No restriction of intake-air system Proper sealing of intake manifold and components attached to intake manifold: such as EGR valve Ignition wiring Fuel quality (e.g. proper octane, contamination, winter/summer blend) Electrical connections Smooth operation of throttle valve Are all items normal?	Yes	Go to the next step.
1		No	Service if necessary. Repeat Step 1.
2	Connect WDS or equivalent to DLC-2. Turn ignition switch to ON position (Engine off). Retrieve any DTCs. Are there any DTCs displayed?	Yes	DTC is displayed: Go to appropriate DTC test.
2		No	No DTC is displayed: Go to the next step.
3	Is engine overheating	Yes	Go to symptom troubleshooting "NO. 17 COOLING SYSTEM CONCERNS - OVERHEATING ".
3	Is engine overheating	No	Go to the next step.
4	Connect WDS or equivalent to DLC-2. Access APP1, APP2, RPM, VPWR, MAF, TP_REL and VSS PIDs. Drive vehicle with monitoring PIDs. Are PIDs within specifications? (See PCM INSPECTION .)	Yes	Go to the next step.
4		No	APP1, APP2 PIDs: Inspect if output signal from accelerator position sensor changes smoothly. RPM PID: Inspect CKP sensor and related harness for vibration or intermittent open/short circuit. VPWR PID: Inspect for open circuit intermittently. MAF PID: Inspect for open circuit of MAF sensor and related wire harness intermittently. TP_REL PID: Inspect if output signal from TP sensor changes smoothly. VSS PID: Inspect for open circuit of VSS and related wire harness intermittently.
5	Visually inspect CKP sensor and teeth of crankshaft pulley. Are CKP sensor and teeth of crankshaft pulley normal?	Yes	Go to the next step.
5		No	Replace malfunctioning parts.
6	Inspect spark plug conditions. Is spark plug wet, covered with carbon or grayish white?	Yes	Spark plug is wet or covered with carbon: Inspect for fuel leakage from fuel injector. Spark plug is grayish white: Inspect for clogged fuel injector.
6		No	Install spark plugs on original cylinders. Go to the next step.
7	Remove and shake PCV valve. Does PCV valve rattle	Yes	Go to the next step.
7	Remove and shake PCV valve. Does PCV valve rattle	No	Replace PCV valve.
8	Perform electronic throttle control system operation inspection. (See ELECTRONIC THROTTLE CONTROL SYSTEM INSPECTION .) Does electronic throttle control system work properly	Yes	Go to the next step.
8		No	Repair or replace malfunctioning part according to electronic throttle system operation inspection results.
9	Inspect for restriction in the exhaust system. Is there any restriction?	Yes	Inspect exhaust system.
9		No	Go to the next step.
10	Install fuel pressure gauge between fuel pipe and fuel distributor. Short check connector terminal F/P to body GND using a jumper wire. Turn ignition switch to ON position. Is fuel line pressure correct with ignition switch to ON position? (See FUEL LINE PRESSURE INSPECTION .)	Yes	Go to the next step.
10		No	Zero or low: Inspect fuel pump relay and fuel pump circuit. Inspect for clogged fuel line. If okay, replace fuel pump unit. High: Replace fuel pump unit.
11	Visually inspect for fuel leakage at fuel injector O-ring and fuel line. Service if necessary. Is fuel line pressure held after ignition switch is turned off? (See FUEL LINE PRESSURE INSPECTION .)	Yes	Go to the next step.
11		No	Inspect fuel injector. If fuel injector is okay, replace fuel pump unit.
12	NOTE: The following test is for engine stalling with A/C on. If other symptom exists, go to the next step. Connect a pressure gauge to A/C low and high pressure side lines.Turn A/C on and measure low side and high side pressure.Are pressures within specifications?(See REFRIGERANT PRESSURE CHECK .)	Yes	Go to the next step.
12		No	If A/C is always on, go to symptom troubleshooting "NO. 24 A/C IS ALWAYS ON OR A/C COMPRESSOR RUNS CONTINUOUSLY ". For other symptoms, inspect the following: Refrigerant charging amount Condenser fan operation
13	NOTE: The following test should be performed for symptom with cruise control ON. If other symptoms exist, go to the next step. Inspect cruise control system.Is cruise control system normal?	Yes	Go to the next step.
13		No	Repair or replace malfunctioning parts.
14	Disconnect vacuum hose between purge solenoid valve and intake manifold from purge solenoid valve side. Plug opening end of vacuum hose. Drive vehicle. Does engine condition improve	Yes	Go to the next step. Inspect if purge solenoid valve sticks open mechanically. Inspect EVAP control system.
14		No	Go to the next step.
15	Visually inspect CMP sensor and projections of camshaft pulley. Are CMP sensor and projections of camshaft pulley normal?	Yes	Go to the next step.
15		No	Replace malfunctioning parts.
16	Inspect Variable tumble system operation. (See VARIABLE TUMBLE SYSTEM OPERATION INSPECTION .) Is Variable tumble system normal?	Yes	Go to the next step.
16		No	Repair or replace malfunctioning parts.
17	Inspect EGR system. (See EGR Control System Inspection .) Is EGR system normal?	Yes	Go to the next step.
17		No	Replace malfunctioning parts.
18	Is engine compression correct	Yes	Inspect the following: Valve timing Internal transaxle part (ATX) Clutch (MTX)
18	Is engine compression correct	No	Inspect for cause.
19	Verify test results. If okay, return to diagnostic index to service any additional symptoms. 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 PCM if later calibration is available. Retest.