
MPI –
Troubleshooting
13-20
INSPECTION PROCEDURE FOR TROUBLE SYMPTOMS
INSPECTION PROCEDURE 1
Communication with MUT-
II
is impossible.
(Communication with all systems is impossible.)
Probable cause
The cause is probably a defect in the power supply system (including earth) for the
diagnosis line.
D
Malfunction of the diagnosis connector
D
Malfunction of the harness wire
Measure at the diagnostic connector
B-22.
D
Voltage between 16 and earth
OK: System voltage
NG
Check the following connectors:
<EVOLUTION-IV> B-49, B-75, B-73
<EVOLUTION-V, VI> B-73, B-80
NG
Repair
OK
Check trouble symptom.
NG
Check the harness wire between the
power supply and diagnostic connector,
and repair if necessary.
OK
Measure at the diagnostic connector
B-22.
D
Continuity between 4 and earth
D
Continuity between 5 and earth
OK: Continuity
NG
Check the earth wire, and repair if nec-
essary.
OK
Replace the MUT-
II
.
INSPECTION PROCEDURE 2
MUT-
II
communication with engine-ECU is impossible.
Probable cause
One of the following causes may be suspected.
D
No power supply to engine-ECU.
D
Defective earth circuit of engine-ECU.
D
Defective engine-ECU.
D
Improper communication line between engine-ECU and MUT-
II
D
Malfunction of engine-ECU power supply circuit
D
Malfunction of engine-ECU
D
Open circuit between immobilizer-ECU and diagnosis
connector
OK
Check the engine-ECU power supply and earth circuit.
(Refer to P.13-53, INSPECTION PROCEDURE 45.)
NG
Check the harness wire between engine-ECU and diagnosis con-
nector.
NG
Repair
OK
Check trouble symptom.
Check the following connectors:
B-22, B-65, B-32, B-61
NG
Repair