Mitsubishi FUEL Manual page 71

Inspection procedure 29
Ignition switch-ST system
The ignition switch-ST outputs a HIGH signal to the engine-ECU <M/T> or
engine-A/T-ECU <A/T> while the engine is cranking.
The engine-ECU <M/T> or engine-A/T-ECU <A/T> uses this signal to carry out
functions such as fuel injection control during starting.
<M/T>
Measure at the engine-ECU connector
C-40.
D Disconnect the connector, and
measure at the harness side.
D Voltage between 71 and earth
(Ignition switch: START)
OK: 8 V or more
OK
Check the following connector:
C-40
OK
Check the trouble symptoms.
NG
Replace the engine-ECU.
<A/T>
Check the inhibitor switch
D Continuity between 9 and 10 (Refer to GROUP 23 –
On-vehicle service.)
Measure at the inhibitor switch connector B-72.
D Disconnect the connector, and measure at the harness
side.
D Voltage between 10 and earth (Ignition switch: START)
OK: System voltage
Measure at the engine-A/T-ECU connector C-176.
D Disconnect the connector, and measure at the harness
side.
D Voltage between 58 and earth
(Selector lever position: P or N)
(Ignition switch: START)
OK: System voltage
Check the following connector: C-176
Check the trouble symptoms.
Replace the engine-A/T-ECU.
MPI <4G6> -
NG
Check the following connectors:
C-92, C-105
Check the trouble symptoms.
NG
Repair
OK
OK
OK
NG
Repair
OK
NG
Troubleshooting
Probable cause
D Malfunction of the ignition switch
D Malfunction of the inhibitor switch <A/T>
D Open circuit or short-circuited harness wire of the
ignition switch circuit
D Malfunction of the engine-ECU <M/T>
D Malfunction of the engine-A/T-ECU <A/T>
NG
OK
NG
NG
Replace
NG
Check the following connectors: C-92, C-105
Check the trouble symptoms.
Check the harness wire between inhibitor switch and ignition switch.
Check the ignition switch (Refer to GROUP 54 – Ignition Switch.)
NG
Check the following connector: B-72
Check the trouble symptoms.
Check the harness wire between inhibitor switch and engine-A/T-
ECU, and repair if necessary.
13A-71
Repair
Check the harness wire between the
engine-ECU and the ignition switch.
NG
OK
Repair
Check the ignition switch.
(Refer to GROUP 54.)
OK NG
Repair
NG
OK NG
Repair
OK NG
Repair
NG