Mitsubishi MOTORS Space Runner 1998, Workshop Manual

Page: 483 / 1164

AUTOMATIC TRANSMISSION -
Troubleshooting
23-23
Code No. 51 Abnormal communication with engine-ECU Probable cause
If normal communication is not possible for a continuous period of 1 second or more
when the ignition switch is at the ON position, the battery voltage is 10 V or more
and the engine speed is 450 r/min or more, diagnosis code No. 51 is output. Diagnosis
code No. 51 is also output if the data being received is abnormal for a continuous
period of 4 seconds under the same conditions.
D Malfunction of connector
D Malfunction of the engine-ECU
D Malfunction of the A/T-ECU
Replace the A/T-ECU.
NG
Check the trouble symptoms.
NG
Replace the engine-ECU.
OK
Check the trouble symptoms.
OK
Harness check
D Between engine-ECU and A/T-ECU
NG
Repair
Check the following connectors:
D B-54, B-52, B-10 <4G93>
D B-53, B-52, B-10 <4G64>
NG
Repair
Code No. 54 A/T control relay system Probable cause
If the A/T control relay voltage is less than 7 V after the ignition switch has been
turned ON, it is judged that there is an open circuit or a short
-
circuit in the A/T control
relay circuit and diagnosis code No. 54 is output.
Then the transmission is locked into 3rd gear as a fail
-
safe measure, and the N
range lamp flashes at a frequency of 1 Hz.
D Malfunction of the A/T control relay
D Malfunction of connector
D Malfunction of the A/T-ECU
Check the A/T control relay. (Refer to P.23-52.)
NG
Replace
OK
Check the following connectors:
A-12X, A-29, B-12, B-10
NG
Repair
OK
Harness check
D Between control relay and body earth
D Between control relay and fusible link
D Between control relay and A/T-ECU
NG
Repair
OK
Check the trouble symptoms.
NG
Replace the A/T-ECU.