Ignition Coil Primary Circuit Malfunction

DTC P0350 DETECTION CONDITION & POSSIBLE CAUSES

DTC P0350	IGNITION COIL PRIMARY CIRCUIT MALFUNCTION
DETECTION CONDITION	P0350 indicates that the powertrain control module (PCM) did not receive a valid ignition diagnostic monitor (IDM) pulse signal, which indicates that the primary side of the coil has failed, from the ignition module (integrated in the PCM) which is caused by an ignition coil primary/secondary circuit malfunction.
POSSIBLE CAUSE	Open or short in ignition START/RUN circuit Open coil driver circuit Coil driver circuit shorted to ground Damaged coil Coil driver circuit shorted to VPWR
HINT	Ignition Coil Description Coil packs come in a tower configuration with two adjacent coil towers sharing a common coil (and called a matched pair). For 4 cylinder applications, the matched pairs are 1 and 4, and 2 and 3 For 6 cylinder applications, the matched pairs are 1 and 5, 2 and 6, and 3 and 4 When the coil is fired by the PCM, spark is delivered to a matched pair of towers to their respective spark plugs. The spark plugs are fired simultaneously and are paired so that as one fires on the compression stroke, the other spark plug fires on the exhaust stroke The next time the coil is fired, the situation is reversed with the next pair of spark plugs being fired according to the engine firing order
Courtesy of MAZDA MOTORS CORP.
Courtesy of MAZDA MOTORS CORP.
Courtesy of MAZDA MOTORS CORP.
Courtesy of MAZDA MOTORS CORP.

DTC P0350 DIAGNOSTIC PROCEDURE

DTC P0350		IGNITION COIL PRIMARY CIRCUIT MALFUNCTION
STEP	INSPECTION		ACTION
1	Was the PCM quick test performed?	Yes	Go to next step.
1	Was the PCM quick test performed?	No	Perform PCM quick test. See PCM QUICK TEST .
2	VISUAL INSPECTION Visually inspect the engine compartment to make sure all vacuum hoses and spark plug wires are properly routed and securely connected. Examine all wiring harnesses and connectors for damaged, burned or overheated insulation and loose or broken conditions. Make certain the battery is fully charged. All accessories must be off during diagnosis. Is a problem indicated?	Yes	Repair as necessary. Go to step 12.
2		No	For ignition coil application using engine analyzer: Go to next step. For ignition coil application not using engine analyzer: Go to step 7.
3	CONNECT ENGINE ANALYZER Obtain engine analyzer to diagnose concerns in the secondary side of the ignition system. NOTE: In order for the diagnostic procedures to provide accurate results, it is essential that the calibration of the engine analyzer be maintained. See the equipment manual for the procedure to calibrate the engine analyzer. If the equipment manual is not available, an estimate of the calibration can be made by connecting a Spark Tester to a properly operating ignition system and measuring the firing voltage of the spark tester only. The spark tester firing voltage should be approximately 28KV. Is the engine analyzer connected?	Yes	Go to next step.
3		No	Repeat this step.
4	CHECK FOR IGNITION PATTERN Observe pattern on scope while cranking engine. See figure A. Is the pattern flat which indicates no spark on all cylinders?	Yes	IGN START/ON (RUN) circuit concern. Key OFF. Verify integrity of fuse 11 in engine compartment fuse box. If OK, repair open circuit. If fuse/fuse link is damaged, check IGN START/ON (RUN) circuit for short to ground. Repair as necessary. Go to step 12.
4		No	Go to next step.
5	CHECK FOR NORMAL IGNITION PATTERN NOTE: Spark plugs are fired up to four strikes per firing. Multi-strike operating mode is dependent on the PCM calibration and is limited to less than 2, 000 rpm. Above 2, 000 rpm, spark plugs are fired once per firing. Key on, engine running (KOER). Check spark plug firing voltage average and evenness of patterns. See figure B. Are all patterns even and is the average value of spark plug firing voltage 20KV or greater with evenness of spark plug firing voltage 8KV or less?	Yes	If you were directed to this diagnosis from a symptom diagnosis chart, return to that symptom diagnosis chart. All others, See GENERAL PINPOINT TEST 4: INTERMITTENT .
5		No	Go to next step.
6	CHECK PATTERN ON SCOPE Observe pattern on scope and look for anything unusual. See figures C-G for unusual signal patterns. Does pattern appear normal?	Yes	Go to next step.
6		No	Inspect spark plug wires and spark plugs. Measure resistance of spark plugs. Replace if greater than 7, 000 ohms per foot (30.5 cm). See SPARK PLUG WIRE REMOVAL / INSTALLATION - 2.3L/3.0L/4.0L . Check spark plug gaps. Adjust if necessary. Measure resistance of spark plugs. Replace if lower than 2, 000 or higher than 20, 000 ohms. See SPARK PLUG REMOVAL / INSTALLATION . Go to step 11.
7	DTC P0301 THROUGH P0306: MISFIRE ON CYLINDERS 1 THROUGH 6 Are any of the above listed DTCs present?	Yes	Go to next step.
7		No	Go to step 9.
8	CHECK FOR SPARK AT CYLINDER(S) INDICATED BY DTC(S) Disconnect the inertia fuel shutoff switch connector. Connect a spark tester and check for spark at suspect cylinder while cranking engine. Is the bluish-white spark present?	Yes	Key OFF. Go to step 10.
8		No	Key OFF. Inspect spark plugs at missing cylinders. Measure resistance of spark plugs. Replace spark plug if lower than 2, 000 or higher than 20, 000 ohms. Go to step 12.
9	CHECK FOR SPARK AT ALL CYLINDERS Disconnect the inertia fuel shutoff switch connector. Using a spark tester check for spark at each cylinder while cranking engine. Is the bluish-white spark consistent between all cylinders?	Yes	Key OFF. Go to next step.
9		No	Key OFF. Measure resistance of spark plugs. Replace spark plug if lower than 2, 000 or higher than 20, 000 ohms. Go to step 12.
10	CHECK SPARK PLUGS Remove and check plugs for damage, wear, carbon deposits and proper plug gap. Are plugs OK?	Yes	Go to next step.
10		No	Repair plugs. Adjust gap or replace as necessary. Go to step 12.
11	CHECK SPARK PLUG RESISTANCE Measure spark plug resistance. Is resistance between 2, 000 and 20, 000 ohms?	Yes	If you were directed to this diagnosis from a symptom diagnosis chart, return to that symptom diagnosis chart. All others, See GENERAL PINPOINT TEST 4: INTERMITTENT .
11		No	Replace spark plugs. See SPARK PLUG REMOVAL / INSTALLATION . Go to next step.
12	DRIVE CYCLE Connect all disconnected connectors. Clear DTCs from PCM memory using WDS or equivalent tester. Perform misfire monitor drive cycle. See DRIVE CYCLES . Retrieve pending code. Is same DTC present?	Yes	Replace PCM. See POWERTRAIN CONTROL MODULE (PCM) REMOVAL / INSTALLATION . Go to next step.
12		No	Go to next step.
13	VERIFY TROUBLESHOOTING OF DTCs COMPLETED Perform PCM quick test. Is any DTC present?	Yes	Go to applicable DTC inspection. See DIAGNOSTIC TROUBLE CODE (DTC) INDEX - POWERTRAIN CONTROL MODULE (PCM) .
13		No	Troubleshooting is complete.