MPI <4G63>
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Troubleshooting
13D-39
INSPECTION PROCEDURE FOR TROUBLE SYMPTOMS
INSPECTION PROCEDURE 1
Communication with M.U.T.-
II/III
is not possible.
(Communication with all systems is not possible.)
Probable cause
The cause is probably a defect in the power supply system (including earth) for the
diagnosis line.
D
Malfunction of the connector
D
Malfunction of the harness wire
Measure at the diagnosis connector
(16-pin) C-11.
D
Voltage between 16 and earth
OK:
System voltage
NG
Check the following connectors:
C-212, C-211, C-21
NG
Repair
OK
Check the trouble symptom.
NG
Check the harness wire between the
power supply and diagnostic connector
(16 pin), and repair if necessary.
OK
Measure at the diagnosis connector
(16-pin) C-11.
D
Continuity between 4 and earth
D
Continuity between 5 and earth
OK:
Continuity
NG
OK
Replace the M.U.T.-
II/III
.
Check the harness wire between the
diagnostic connector (16-pin)andearth,
and repair if necessary.
INSPECTION PROCEDURE 2
M.U.T.-
II/III
communication with engine-A/T-ECU is
impossible.
Probable cause
One of the following causes may be suspected:
D
No power supply to engine-A/T-ECU.
D
Defective earth circuit of engine-A/T-ECU.
D
Defective engine-A/T-ECU.
D
Improper communication line between engine-A/T-ECU and M.U.T.-
II/III
D
Malfunctionoftheengine-A/T-ECUpowersupplycircuit
D
Malfunction of the engine-A/T-ECU
D
Open circuit between engine-A/T-ECU and diagnosis
connector
OK
Check the following connectors:
C-11, C-32, C-13, C-126
NG
Repair
Check the trouble symptom.
NG
Check the harness wire between engine-A/T-ECU and diagnosis
connector.
OK
Check the harness wire
betweenengine-A/T-ECU
and earth.
NG
Repair
NG
Repair
OK
Check the power supply system and ignition switch-IG system.
(Refer to P.13D-59, INSPECTION PROCEDURE 27.)