MITSUBISHI TRITON 1997 Workshop Manual

CHASSIS ELECTRICAL ± Ignition Switch and Immobilizer System54-12
Code No.21 Communication system between MUT-II and
engine-ECUProbable cause
After the ignition switch turned to ON, the confirmation code is not received from
the engine-ECU within allowable time, or an abnormal code is received.
Malfunction of harness or connector

Malfunction of engine-ECU

Malfunction of immobilizer-ECU
Is diagnosis code No.54 displayed from
the engine-ECU?Ye sCheck the engine-ECU power source
and the earth circuit. (Refer to GROUP
13A ± Troubleshooting.)
No
Check the following connectors:
C-19, C-36, C-50NG
Repair
OK
Check trouble symptom.NGCheck the harness between the engine-
ECU and immobilizer-ECU.NG
Repair
OK
Check trouble symptom.
NG
Replace the immobilizer-ECU.
Register the password (secret code)
and ID code. (Refer to P.54-23.)
Check trouble symptom.NGReplace the engine-ECU.
Code No.31 EEPROM abnormality inside immobilizer-
ECUProbable cause
No data has been written to the EEPROM inside the immobilizer-ECU.
Malfunction of immobilizer-ECU
Check trouble symptom.NGReplace the immobilizer-ECU.Register the password (secret code)
and ID code. (Refer to P.54-23.)

CHASSIS ELECTRICAL ± Ignition Switch and Immobilizer System54-13
INSPECTION CHART FOR DIAGNOSIS CODES

54300710034
Diagnosis code No.Inspection itemsReference page
11Transponder communication system or radio interference of ID
code54-11
12*ID codes are not the same or not registered54-11
21Communication system between fuel cut valve controller and
immobilizer-ECU54-13
22Malfunction of fuel cut valve controller system54-14
23Identification codes are not identical54-14
31EEPROM abnormality inside immobilizer-ECU54-12
NOTE
*: diagnosis code No.12 is recorded.
INSPECTION PROCEDURE FOR DIAGNOSIS CODES

For diagnosis code numbers other than those listed below, refer to ªPETROL-POWERED VEHICLESº.
Code No.21 Communication system between fuel cut
valve controller and immobilizer-ECU
Probable cause
The confirmation code is not sent from the fuel cut valve controller within the specified
time after the ignition key is turned to ON or, an incorrect code is sent.
Malfunction of harness or connector

Malfunction of fuel cut valve controller

Malfunction of immobilizer-ECU
Check the following connectors: A-90, C-19, C-36NG
Repair
OK
Check trouble symptom.
NG
Check the harness between the immobilizer-ECU and fuel cut valve
controller.NG
Repair
OK
Check the fuel cut valve controller power source and earth circuit.
(Refer to P.54-17, Inspection Procedure 6.)NG
Repair
OK
Check trouble symptom.NGReplace the immobilizer-ECU.
Register the password (secret code), reset the code to the factory
setting and register the ID code. (Refer to P.54-23.)
Check trouble symptom.
NG
Replace the fuel cut valve controller (fuel injection pump assembly).

CHASSIS ELECTRICAL ± Ignition Switch and Immobilizer System54-14
Code No.22 Malfunction of fuel cut valve controller
systemProbable cause
The cause is probably a malfunction of the fuel cut valve controller.
Malfunction of fuel cut valve controller
Check the fuel cut valve controller power source and earth circuit.
(Refer to P.54-17, Inspection Procedure 6.)
OK
Check trouble symptom.NGReplace the fuel cut valve controller (fuel injection pump assembly).
Code No.23 Identification codes are not identicalProbable cause
The identification code received from the immobilizer-ECU is not identical to the
identification code that has been recorded in the fuel cut valve controller.
Resetting the code to the factory setting is not made
using the MUT-II

Malfunction of fuel cut valve controller
Use the MUT-II to reset the code to the factory setting.
(Refer to P.54-23.)
Check trouble symptom.NGReplace the fuel cut valve controller (fuel injection pump assembly).
Check trouble symptom.
NG
Replace the immobilizer-ECU.
Register the password (secret code), reset the code to the factory
setting and register the ID code. (Refer to P.54-23.)
INSPECTION CHART FOR TROUBLE SYMPTOMS54300720242
Trouble symptomInspection procedure No.Reference page
Communication with MUT-II is impossible154-15
ID code cannot be registered using the MUT-II254-15
Engine does not start (Cranking but no initial combustion).
354-16
Engine does not start (Cranking but no initial combustion).
454-16
Malfunction of the immobilizer-ECU power source and
earth circuit554-17
Malfunction of the fuel cut valve controller power source
and earth circuit 654-17

CHASSIS ELECTRICAL ± Ignition Switch and Immobilizer System54-15
INSPECTION PROCEDURE FOR TROUBLE SYMPTOMS
Inspection Procedure 1
Communication with MUT-II is impossible
Probable cause
The cause is probably that a malfunction of the diagnosis line or the immobilizer-ECU
ia not functioning.
Malfunction of diagnosis line

Malfunction of harness or connector

Malfunction of immobilizer
Ye sOK
Check trouble symptom.
NG
OK
Check trouble symptom.NG
Check the harness between the immobi-
lizer-ECU and diagnosis connector.NG
Repair
OK
Check the immobilizer-ECU power sup-
ply and earth circuit. (Refer to P.54-17,
Inspection Procedure 5.)
OK
Check trouble symptom.NGReplace the immobilizer-ECU.

Register the password (secret code)
and the ID code. (Refer to P.54-23.)

Register the password (secret code),
reset the code to the factory setting and
register the ID code. (Refer to P.54-23.)
Check the immobilizer-ECU connector
C-36.
(Short-circuited harness wire between
terminal No.14 and No.15)NG
Repair
Can the MUT-II communicate with the
engine-ECU?NoCheck the following connectors:
C-35, C-36NG
Repair
Inspection Procedure 2
ID code cannot be registered using the MUT-II
Probable cause
The cause is probably that there is no ID code registered in the immobilizer-ECU
or there is a malfunction of the immobilizer-ECU.
Malfunction of transponder

Malfunction of ignition key ring antenna

Malfunction of harness or connector

Malfunction of immobilizer-ECU
No ignition key can be registered.NoReplace the ignition key that cannot be
registered.Re-register the ID code.
(Refer to P.54-23.)
Ye s
Is a diagnosis code displayed?Ye sTo INSPECTION CHART FOR DIAG-
NOSIS CODE. (Refer to P.54-10, 13.)
No
Check the immobilizer-ECU power
source and the earth circuit. (Refer to
P.54-17, Inspection Procedure 5.)OKCheck trouble symptom.NGReplace the immobilizer-ECU.

Register the password (secret code)
and the ID code. (Refer to P.54-23.)

Register the password (secret code),
reset the code to the factory setting and
register the ID code. (Refer to P.54-23.)

CHASSIS ELECTRICAL ± Ignition Switch and Immobilizer System54-16
Inspection Procedure 3
Engine does not start (Cranking but no initial combus-
tion).
Probable cause
If the fuel injectors are not operating, there might be a problem with the MPI system
in addition to a malfunction of the immobilizer system.
It is normal for this to occur if an attempt is made to start the engine using a key
that has not been properly registered.
Malfunction of MPI system

Malfunction of immobilizer-ECU
Check the system voltage during crank-
ing
OK:8 V or moreNGCheck the battery.
OK
Is a diagnosis code displayed from the
immobilizer-ECU?Ye sTo INSPECTION CHART FOR DIAG-
NOSIS CODE. (Refer to P.54-10.)
No
Is a diagnosis code displayed from the
engine-ECU?Ye sRefer to GROUP 13A ± Troubleshoot-
ing.
No
Check the starting system. (Refer to
GROUP 13A ± Troubleshooting.)
OK
Check trouble symptom.
NG
Check the immobilizer-ECU power
source and the earth circuit. (Refer to
P.54-17, Inspection Procedure 5.)OKCheck trouble symptom.NGReplace the immobilizer-ECU.
Register the password (secret code)
and the ID code. (Refer to P.54-23.)
Inspection Procedure 4
Engine does not start (Cranking but no initial combus-
tion).
Probable cause
If no fuel injection, there might be a problem with the fuel injection system in addition
to a malfunction of the immobilizer system.
It is normal for this to occur if an attempt is made to start the engine using a key
that has not been properly registered.
Malfunction of diesel fuel injection system

Malfunction of immobilizer-ECU
Check the system voltage during crank-
ing
OK:8 V or moreNGCheck the battery.
OK
Is a diagnosis code displayed from the
immobilizer-ECU?Ye sTo INSPECTION CHART FOR DIAG-
NOSIS CODE. (Refer to P.54-13.)
No
Check the diesel fuel injection system.
(Refer to GROUP 13E ± On-vehicle Ser-
vice.)
OK
Check the immobilizer-ECU power sup-
ply and the earth circuit. (Refer to
P.54-17, Inspection Procedure 5.)OKCheck trouble symptom.NGReplace the immobilizer-ECU.
Register the password (secret code),
reset the code to the factory setting and
register the ID code. (Refer to P.54-23.)
Check trouble symptom.
NG
Replace the fuel cut valve controller
(fuel injection pump assembly).

CHASSIS ELECTRICAL ± Ignition Switch and Immobilizer System54-17
Inspection Procedure 5
Malfunction of the immobilizer-ECU power source and earth circuit
Measure at the immobilizer-ECU con-
nector C-36.

Disconnect the connector and
measure at the harness side.

Ignition switch: ON
1. Voltage between 1 and body earth,
2 and body earth vehicles> and between 9 and body
earth.
OK:System voltage
2. Continuity between 8 and body earth
and between 16 and body earth.
OK:Continuity(1) NGCheck the following connectors:

C-19, C-36, C-87, C-83

C-36, C-87, C-83NG
Repair
OK
Check trouble symptom.NG
Check the harness between the immobi-
lizer-ECU and engine control relay, and
repair if necessary.

Check the harness between the immobi-
lizer-ECU and junction block, and repair
if necessary.
(2) NG
Check the following connector:
C-36NG
Repair
OK
Check trouble symptom.NGCheck the harness between the immobi-
lizer-ECU and body earth and repair if
necessary.
Inspection Procedure 6
Malfunction of the fuel cut valve controller power source and earth circuit

OK
Check trouble symptom.NGCheck the harness between the fuel cut
valve controller and junction block, and
repair if necessary.
(2) NGCheck the following connector:
A-90NG
Repair
OK
Check trouble symptom.NGCheck the harness between the fuel cut
valve controller and earth, and repair
if necessary.
Measure at the fuel cut valve controller
connector A-90.

Disconnect the connector and
measure at the harness side.

Ignition switch: ON
1. Voltage between 2 and body earth.
OK:System voltage
2. Continuity between 3 and body
earth.
OK:Continuity(1) NGCheck the following connectors:
A-90, C-19, C-87NG
Repair

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