PleasureCraft Engine Group 5.0L, Diagnostic Manual, Page: 215 / 337

5.0/5.7/6.0/8.1L Diagnosis 5 - 73
MEFI 4 - PCM
Diagnostic Procedure (DP) A-7A Distributor Ignition Diagnosis (5.0/5.7L Only)
Step Action Value Yes No
1
Was the “On-Board Diagnostic” (OBD) system check Go to OBD
performed? — Go to Step 2 System Check
Caution: Before proceeding, remove all injector
connectors and the ignition module connector (5.0/5.7L),
or disconnect the harness connectors at the ignition
coils and the injectors(6.0/8.1L) in order to prevent
personal injury from engine rotation, sparks and
excessive engine fueling.
1. Turn ON the ignition leaving the engine OFF.
2
2. Disconnect the Crankshaft Position (CKP) sensor
harness connector.
3. Using a DMM connected to a known good ground,
measure the voltage at terminal “A” (Depspower) at
the CKP sensor harness.
Does the DMM display the specifi ed value? B+ Go to Step 3 Go to Step 21
Using a DMM, measure the voltage between the CKP
3
sensor harness connector terminals “A” (Depspower) and
“B” (Depslo).
Does the DMM display the specifi ed value? B+ Go to Step 4 Go to Step 22
1. Turn ignition “OFF.”
2. Disconnect the ECM “J2” connector.
4
3. Using a DMM, measure resistance between terminal
“C” of the CKP sensor and ECM harness connector
“J2-16.”
Does the DMM display the specifi ed value? 0 ohms Go to Step 5 Go to Step 23
1. Check the spark plug wires for open circuits, cracks or
improper seating of terminals at the spark plugs,
distributor and ignition coil before proceeding with the
test.
5
2. Using a timing light, check for spark on a plug wire
while cranking the engine. If there is no spark on one
wire, check a second wire. A few fl ashes then nothing is
considered no spark.
Does the timing light fl ash while cranking the engine, on all Go to
cylinders? — Diagnostic Aids Go to Step 6
Using a timing light, check for spark on the coil wire while
cranking the engine. A few fl ashes then nothing is
6
considered no spark.
Does the timing light fl ash while cranking the engine? — Go to Step 15 Go to Step 7
Measure the coil wire resistance.
7
Does the resistance measure approximately the specifi ed
value? 1,000 ohm/in. Go to Step 8 Go to Step 36
1. Disconnect the ignition coil harness connector.
8
2. Using a test lamp connected to B+, probe the ignition
coil driver circuit, terminal “C.”
Does the test lamp fl ash while cranking the engine? — Go to Step 10 Go to Step 9