Mercury MerCruiser MCM 454 Mag MPI Service Manual page 663

GENERAL SYSTEM DIAGNOSTICS
Chart A-3 (5 of 5): Engine Cranks But Will Not Run
Step
18
19
20
21
22
Index
Page 5E-70
Downloaded from https://needmanual.com/
Action
Locate and repair open in CKT 467
or CKT 468.
Is Action Complete?
Check for short to ground in CKT
467 or CKT 468. If a problem is
found, repair as necessary.
Was A Problem Found?
Check the injector driver circuit
with the steady light for a short to
ground. If circuit is not shorted,
check resistance across injector in
the circuit.
Is Resistance Close To The
Specified Value?
1. All checks made to this point
would indicate that the ECM is
at fault. However, there is a
possibility of CKT 467 and CKT
468 being shorted to a voltage
source in the engine harness
or the injector harness.
2. Disconnect all injectors.
3. Ignition "ON".
4. Using a test light connected to
ground, probe CKT 467 and
CKT 468 on the ECM side of
the injector harness (Test one
injector harness on each side
of the engine). If light is "ON",
locate and repair short to volt-
age.
5. Check injector harness con-
nector. Be sure that terminals
are not backed out of connec-
tor and contacting each other.
6. If all OK, replace faulty ECM.
Is Action Complete?
Repair faulty ECM connections or
replace faulty ECM.
Is Action Complete?
SERVICE MANUAL NUMBER 23
Value(s) Yes
Go to OBD
System Check
–
Go to OBD
System Check
–
Go to OBD
System Check
–
Go to OBD
System Check
–
Go to OBD
System Check
–
90-861326--1 MARCH 1999
No
–
–
–
–
–