Mitsubishi MOTORS Space Runner 1999 Workshop Manual Supplement page 88

Code No.54 Immobilizer system
Range of Check
D Ignition switch: ON
Set Conditions
D Improper communication between the engine-ECU <M/T> or engine-A/T-ECU <A/T>
and immobilizer-ECU
NOTE
(1) If the ignition switches are close each other when starting the engine, radio interference may cause
this code to be displayed.
(2) This code may be displayed when registering the key ID code.
Is there another ignition key near the ignition key that is inserted
in the ignition switch?
Is a diagnosis code output from the immobilizer-ECU?
Check the following connectors:
B-52 <M/T>, B-110 <A/T>, B-14, B-82
Check trouble symptom.
Check the harness wire between the engine-ECU <M/T> or engine-
A/T-ECU <A/T> and the immobilizer-ECU.
Repair
MPI -
No
No
OK
NG
NG
Troubleshooting
Probable cause
D Radio interference of ID codes
D Incorrect ID code
D Malfunction of harness or connector
D Malfunction of immobilizer-ECU
D Malfunction of engine-ECU <M/T> or engine-A/T-ECU
<A/T>
Yes
Remove the extra ignition key.
NG
Check trouble symptom.
Yes
Check the immobilizer system. (Refer to GROUP 54 - Ignition
Switch and Immobilizer System.)
NG
Repair
OK
Replace the immobilizer-ECU.
Check trouble symptom.
Replace the engine-ECU <M/T> or engine-A/T-ECU <A/T>.
13D-23
NG
NG