Diagnostic Procedures

WARNING: This page is about a different car, the 2002 Mazda B4000, 2002 Mazda B3000, and 2002 Mazda B2300. However, it is still accessible from the selected car via links, so may be relevant.

If QUICK TEST was not performed, go to QUICK TEST under SELF-DIAGNOSTIC SYSTEM. If QUICK TEST was performed, go to next step.
NOTE: Electronic ignition engine timing is PCM controlled. Electronic ignition timing is NOT adjustable. DO NOT attempt to check base timing. Base timing ignition readings will be inaccurate.

Determine Which Coil Is Not Firing

Determine which coil is not firing using information from IGNITION COIL-TO-CYLINDER CORRELATION (COIL PACK) table. Record cylinder, coil and breakout box terminal from table. If cylinder number, coil driver and PCM pin numbers have been recorded, go to next step. If information has not been recorded, obtain required information. Go to next step.

IGNITION COIL-TO-CYLINDER CORRELATION (COIL PACK)

Application & Cylinder No.	Coil Driver	Breakout Box Terminal No.	DTC
2.3L
1	1	26	P0351
3	2	52	P0352
4	1	26	P0351
2	2	52	P0352
3.0L & 4.0L
1	1	26	P0351
4	2	52	P0352
2	3	78	P0353
5	1	26	P0351
3	2	52	P0352
6	3	78	P0353

Check IGN START/RUN Voltage To Coil Pack

Disconnect coil. With KOEO, measure voltage of IGN START/ON (RUN) circuit between ignition coil harness connector and ground. See Fig 1 -Fig 3 . Record reading. Turn ignition off. If voltage is more than 10 volts, go to next step. If voltage is 10 volts or less, a fault is present in IGN START/ON (RUN) circuit. Check fuse No. 19 in instrument panel fuse panel. If fuse is okay, repair open circuit. See WIRING DIAGRAMS article. If fuse is open, check IGN START/ON (RUN) circuit for short to ground. Repair as necessary. See WIRING DIAGRAMS article. Go to step 12 .

Fig 1: Identifying Coil Harness Connector (2.3L)
Courtesy of MAZDA MOTORS CORP.

Fig 2: Identifying Coil Harness Connector (3.0L)
Courtesy of MAZDA MOTORS CORP.

Fig 3: Identifying Coil Harness Connector (4.0L)
Courtesy of MAZDA MOTORS CORP.

Check Functionality Of Suspect Coil Driver (CD) Circuit

Connect test light between IGN START/ON (RUN) circuit and suspect CD circuit (determined from IGNITION COIL-TO-CYLINDER CORRELATION (COIL PACK) table) at the ignition coil harness connector. Disconnect inertia fuel shutoff switch to disable fuel pump. Observe test light while cranking engine. If test light blinked consistently, go to step 10 . If test light did not blink consistently, go to next step.

Check Suspect CD Circuit For Open In Harness

Turn ignition off. Disconnect PCM connector. Install breakout box, leaving PCM disconnected. Measure resistance of suspect CD circuit between breakout box terminal and ignition coil harness connector (determined from IGNITION COIL-TO-CYLINDER CORRELATION (COIL PACK) table). If resistance is less than 5 ohms, go to next step. If resistance is 5 ohms or more, repair open circuit. See WIRING DIAGRAMS article. Go to step 12 .

Check Suspect CD Circuit For Short To VPWR In Harness

With KOEO, measure voltage of suspect CD circuit between breakout box terminal (determined from IGNITION COIL-TO-CYLINDER CORRELATION (COIL PACK) table) and ground. Turn ignition off. If voltage is less than one volt, go to next step. If voltage is one volt or more, repair short circuit. See WIRING DIAGRAMS article. Go to step 12 .

Check Suspect CD Circuit For Short To Ground In Harness

Disconnect scan tool. Measure resistance of suspect CD circuit between breakout box terminal (determined from IGNITION COIL-TO-CYLINDER CORRELATION (COIL PACK) table) and ground. If resistance is more than 10,000 ohms, go to next step. If resistance is less than 10,000 ohms, repair short circuit. See WIRING DIAGRAMS article. After repair, go to step 9 to check for damaged coil.

Perform Intermittent Test On Suspect CD Circuit Harness

Connect DVOM to suspect CD circuit between breakout box terminal (determined from IGNITION COIL-TO-CYLINDER CORRELATION (COIL PACK) table) and ignition coil harness connector. While observing DVOM, wiggle and bend CD harness from PCM to ignition coil harness connector. If resistance fluctuates, repair intermittent fault in harness. See WIRING DIAGRAMS article. Go to step 12 . If resistance does not fluctuate, replace faulty PCM. After repair, go to step 9 to check for damaged coil.

Check Suspect Primary Coil For Open

Measure resistance of suspect coil between CD and IGN START/ON (RUN) circuits at ignition coil connector. If resistance is less than 5 ohms, go to step 12 . If resistance is 5 ohms or more, replace faulty ignition coil. Go to step 12 .

Check Suspect Secondary Coil For Open

Measure resistance between CD and IGN START/ON (RUN) circuits at ignition coil connector. If resistance is less than 5 ohms, go to step 12 . If resistance is 5 ohms or more, replace faulty ignition coil. Go to step 12 .
NOTE: Ignition coil resistance for 2.3L engine is not available from manufacturer.

Check Suspect Secondary Coil For Open

Remove both plug wires from ignition coil of suspect cylinder. Measure resistance of suspected coil driver between terminals. Resistance specifications are 8600-11,100 ohms (3.0L) or 11,500-15,500 ohms (4.0L). If resistance is within specification and DTC P0350 is set, go to DTC P0350: IGNITION COIL CIRCUIT MALFUNCTION . If resistance is within specification and no additional ignition DTCs are set, go to INTERMITTENT under SYSTEM TESTS. If resistance is not within specification, replace faulty ignition coil. Go to next step.

Drive Cycle

Reconnect all electrical connectors. Using scan tool, clear DTC memory. Perform FUEL OR MISFIRE MONITOR REPAIR VERIFICATION DRIVE CYCLE in MONITOR REPAIR VERIFICATION DRIVE CYCLES under DRIVE CYCLE PROCEDURES. Using scan tool, retrieve DTCs. If same DTC is not present, go to next step. If same DTC is present, replace faulty PCM. Go to next step.

Verify Trouble Shooting Of DTCs Completed

Perform QUICK TEST under SELF-DIAGNOSTIC SYSTEM. If any DTC is present, go to applicable procedure for other DTCs. See DIAGNOSTIC TROUBLE CODE DEFINITIONS . If no DTCs are set, trouble shooting is complete.