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