PleasureCraft Engine Group 5.0L, Diagnostic Manual, Page: 189 / 337

5.0/5.7/6.0/8.1L Diagnosis 5 - 47
MEFI 4 - PCM
Important:
•
Do not perform this diagnostic if there is not a
drivability concern, unless another procedure directs
you to that diagnostic.
•
Before you proceed with diagnosis, search for
applicable service bulletins.
•
Before you proceed with diagnosis, perform
a visual inspection of the engine for damaged
wiring, connections, or assemblies.
•
Unless a diagnostic procedure instructs you, DO NOT
clear the DTC’s.
•
If there is a condition with the starting system, repair
1
that fi rst.
•
Ensure the battery has a full charge.
•
Ensure the battery cables are clean and tight.
•
Ensure the ECM grounds are clean, tight and in the
correct location.
1. Ignition “ON,” engine “OFF.”
2. Install Diacom Diagnostic Scan tool
3. Attempt to display ‘ECM Data’
Does the scan tool display ‘ECM Data’? — Go to Step 2 Go to Step 10
1. Using Diacom, display ‘ECM Data’.
2
2. Ignition “ON,” engine “OFF.”
3. Observe the Malfunction Indicator Lamp on the
ECM data display.
Is the Malfunction Indicator Lamp “ON”? — Go to Step 3 Go to DP-A1
1. Using Diacom, display ‘ECM Data’.
3
2. Ignition “ON,” engine “OFF.”
3. Observe the Malfunction Indicator Lamp on the
ECM data display.
Does the Malfunction Indicator Lamp fl ash DTC 12? — Go to Step 4 Go to Step 5
1. Verify a known good Diacom scan tool.
4
2. Check CKT 451 for a short to ground.
3. If a problem is found, repair as necessary. Repeat OBD
Was a problem found? — System Check Go to Step 13
On-Board Diagnostic (OBD) System Check - Scan
Step Action Value Yes No
Test Description (continued)
6. When you return to the Diacom ‘Tests’ menu to disable
the base timing mode, fi rst select “Activate Base Timing
Mode” then select “Disable Base Timing Mode”. When
you return to the ‘ECM Data’ display you will have to
re-link to the ECM to display data.
7. If the engine will not start, DP A-3 should be used to
diagnose this condition.
8. Troubleshoot DTC(s) fi rst. If Logged Warnings are
displayed, refer to the chart on page 5-11 for the circuit
affected. Troubleshoot and repair the condition that
caused the Logged Warning, then Repeat the OBD
System Check.
9. A scan tool parameter which is not within the typical
range may help to isolate the area which is causing the
problem.
12. a. Verify your Diacom Installation and cables on a
known good engine.
b. Verify that no auxiliary devices are plugged into the
serial data line. Normally, aftermarket devices are wired
in at the DLC connector and are disconnected when
Diacom is connected. Verify that no device is wired in
at pin-10 of the engine’s 10-pin main harness connector,
and pin-10 is an open connection.