Test 15: Ignition Scope Test

CAUTION:

Fouled plugs or a damaged ignition may cause high catalyst temperatures. Check components next to the catalyst and muffler for heat damage.

2.3L

IGNITION SCOPE TEST CHART

Firing Order	Ignition Coil
1	1
3	3
4	4
2	2

3.0L

IGNITION SCOPE TEST (3.0L)

Firing Order	Ignition Coil
1	1
4	4
2	2
5	5
3	3
6	6

IGNITION SCOPE TEST

TEST 15		IGNITION SCOPE TEST
STEP	INSPECTION		ACTION
1	VISUAL INSPECTION OF IGNITION SYSTEM Visually inspect the engine compartment to make sure all coils and spark plug wires are properly and securely connected. Examine all wiring harnesses and connectors for damaged, burned or overheated insulation and loose or broken conditions. Be certain the battery is fully charged. All accessories must be off during diagnosis. Is a problem indicated?	Yes	REPAIR as necessary. COMPLETE Misfire Monitor Repair Verification Drive Cycle. DRIVE CYCLE .
1		No	For diagnosis with engine analyzer, go to next step. For diagnosis without engine analyzer, go to step 10.
2	CONNECT ENGINE ANALYZER Obtain engine analyzer 010-01060 or an equivalent 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 the Spark Tester 303-D037 or equivalent 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.
2		No	Repeat step 2.
3	CHECK FOR IGNITION PATTERN Observe pattern on scope while cranking engine. See Figure at the end of this test. Is the pattern flat which indicates no spark on all cylinders?	Yes	IGN START/RUN circuit concern. Key OFF. CHECK condition of related fuses/fuse links. If OK, REPAIR open circuit. If fuse/fuse link is damaged, CHECK IGN START/RUN circuit for short to ground. REPAIR as necessary. COMPLETE Misfire Monitor Repair Verification Drive Cycle. See DRIVE CYCLE .
3		No	Go to next step.
4	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 2000 rpm. Above 2000 rpm, spark plugs are fired once per firing. Key ON, Engine OFF (KOEO), Engine Running (KOER). Check spark plug firing voltage average and evenness of patterns. See Figure at the end of this test. Are patterns even and is the average value of spark plug firing voltage 20KV or less with evenness of spark plug firing voltage 8KV or less?	Yes	If you were directed to this Pinpoint Test from the Diagnostic Index, return to DIAGNOSTIC INDEX . If you were directed to this Pinpoint Test from Misfire Detection Monitor step 4, return to MISFIRE DETECTION MONITOR DISABLED . If you were directed to this Pinpoint Test from Test 16: No Start, return to TEST 14: NO START . All others, s TEST 3: INTERMITTENT .
4		No	Go to next step.
5	CHECK FOR TWO MISSING SPARK PATTERNS ON THE SAME COIL Observe pattern on scope. See Figure at the end of this test. Is the spark pattern missing from two cylinders on the same coil?	Yes	INSPECT the spark plugs for missing cylinders. MEASURE resistance of spark plugs. REPLACE if lower than 2000 or higher than 20000 ohms. See IGNITION COIL-ON-PLUG AND SPARK PLUG -- 2.3L , or IGNITION COIL-ON-PLUG AND SPARK PLUG -- 3.0L (4V) . If spark plugs are OK, s IGNITION COIL PRIMARY CIRCUIT MALFUNCTION .
5		No	Go to next step.
6	CHECK FOR ONE MISSING SPARK PATTERN Observe pattern on scope. See Figure at the end of this test. Is spark pattern missing from one cylinder?	Yes	INSPECT spark plug for missing cylinder. MEASURE resistance of spark plug. REPLACE if lower than 2000 or higher than 20000 ohms. See IGNITION COIL-ON-PLUG AND SPARK PLUG -- 2.3L , or IGNITION COIL-ON-PLUG AND SPARK PLUG -- 3.0L (4V) . Complete Misfire Monitor Repair Verification Drive Cycle. See DRIVE CYCLE .
6		No	Go to next step.
7	CHECK FOR HIGH SPARK PLUG FIRING VOLTAGE Check the spark plug firing voltage average and evenness. See Figure at the end of this test. Is the average value of spark plug firing voltage greater than 20KV with evenness of spark plug voltage 8KV or less?	Yes	Conditions affect all cylinders. INSPECT spark plugs. MEASURE resistance of spark plug. REPLACE if lower than 2000 or higher than 20000 ohms. See IGNITION COIL-ON-PLUG AND SPARK PLUG -- 2.3L , or IGNITION COIL-ON-PLUG AND SPARK PLUG -- 3.0L (4V) . Complete Misfire Monitor Repair Verification Drive Cycle. See DRIVE CYCLE .
7		No	Go to next step.
8	CHECK FOR LOW SPARK PLUG FIRING VOLTAGE Check the spark plug firing voltage average and evenness. See Figure at the end of this test. Is there consistently low spark plug firing voltage or sloping spark line on one or more cylinders?	Yes	INSPECT the spark plugs. MEASURE resistance of spark plug. REPLACE if lower than 2000 or higher than 20000 ohms. See IGNITION COIL-ON-PLUG AND SPARK PLUG -- 2.3L , or IGNITION COIL-ON-PLUG AND SPARK PLUG -- 3.0L (4V) . COMPLETE Misfire Monitor Repair Verification Drive Cycle. See DRIVE CYCLE .
8		No	Go to next step.
9	CHECK FOR EVENNESS BETWEEN CYLINDERS Check the spark plug firing voltage average and evenness. See Figure at the end of this test. Is the evenness of spark plug firing voltage greater than 8KV?	Yes	INSPECT spark plugs. MEASURE resistance of spark plug. REPLACE if lower than 2000 or higher than 20000 ohms. See IGNITION COIL-ON-PLUG AND SPARK PLUG -- 2.3L , or IGNITION COIL-ON-PLUG AND SPARK PLUG -- 3.0L (4V) . COMPLETE Misfire Monitor Repair Verification Drive Cycle. DRIVE CYCLE .
9		No	See TEST 3: INTERMITTENT .
10	DTC P0301 THROUGH DTC P0306: MISFIRE ON CYLINDERS 1 THROUGH 6 Are any of the above listed DTCs present?	Yes	Go to next step.
10		No	Goto step 12.
11	CHECK FOR SPARK AT CYLINDER(S) INDICATED BY DTC(S) Disable fuel pump shutoff switch. Disconnect spark plug wire(s) from spark plug(s). Connect a Spark Tester 303-D037 (D81P-6666-A) or equivalent to a spark plug wire. Check for spark while cranking engine. Is the bluish-white spark present?	Yes	Key OFF. Go to step 13.
11		No	Key OFF. COMPLETE Misfire Monitor Repair Verification Drive Cycle. See MISFIRE DETECTION MONITOR DISABLED . See TEST 3: INTERMITTENT .
12	CHECK FOR SPARK AT ALL CYLINDERS Disable fuel pump shutoff switch. Using a Spark Tester 303-D037 (D81P-6666-A) or equivalent, check for spark at each cylinder while cranking engine. Check for spark while cranking engine. Is the bluish-white spark consistent between all cylinders?	Yes	Key OFF. Go to next step.
12		No	Key OFF. COMPLETE Misfire Monitor Repair Verification Drive Cycle. See DRIVE CYCLE . See TEST 3: INTERMITTENT .
13	CHECK SPARK PLUGS Remove and check plugs for damage, wear, carbon deposits and proper plug gap. Are plugs OK?	Yes	Go to next step.
13		No	REPAIR plugs. ADJUST gap or replace as necessary. See IGNITION COIL-ON-PLUG AND SPARK PLUG -- 2.3L , or IGNITION COIL-ON-PLUG AND SPARK PLUG -- 3.0L (4V) . COMPLETE Misfire Monitor Repair Verification Drive Cycle. See DRIVE CYCLE .
14	MEASURE SPARK PLUG RESISTANCE Measure spark plug resistance. Is resistance between 2000 and 20000 ohms?	Yes	If you were directed to this Pinpoint Test from Diagnostic Index, return to DIAGNOSTIC INDEX . If you were directed to this Pinpoint Test from Misfire Detection Monitor step 4, return to MISFIRE DETECTION MONITOR DISABLED step 5. If you were directed to this Pinpoint Test from Test 16: No Start, return to TEST 14: NO START . All others, return to DRIVE CYCLE .
14		No	REPLACE spark plugs. COMPLETE Misfire Monitor Repair Verification Drive Cycle. DRIVE CYCLE .