Mitsubishi Montero (2002-2004). Manual - part 462

IGNITION SWITCH

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CHASSIS ELECTRICAL

54A-19

STEP 10. Recheck for malfunction.
Q: Is a malfunction eliminated? 

YES : The procedure is complete. (If no malfunction are not 

found in all steps, an intermittent malfunction is 
suspected. Refer to GROUP 00, How to Use 
Troubleshooting/Inspection Service Points 

− How to 

Cope with Intermittent Malfunction 

P.00E-2

.)

NO :  Replace the immobilizer-ECU or PCM.

INSPECTION PROCEDURE 2: The Ignition Key cannot be Registered.

.

TECHNICAL DESCRIPTION (COMMENT)
The ignition key transponder or the immobilizer-ECU 
is suspected to be defective.

.

TROUBLESHOOTING HINTS

• Malfunction of the ignition key

• Malfunction of immobilizer-ECU 

.

DIAGNOSIS

Required Special Tools:

• MB991223: Harness Set

• MB991502: Scan Tool (MUT-II)

STEP 1. Check the DTC.
Q: Does DTC11 reset?

YES :  Refer to 

P.54A-8

.

NO :  Replace the ignition key that cannot be registered. 

Then re-register the encrypted code. (Refer to 

P.54A-

22

.) Verify that the ignition key can be registered, then 

Go to Step 2.

STEP 2. Retest the system.
Q: Does registered ignition key function properly?

YES : The procedure is complete. (If no malfunction are not 

found in all steps, an intermittent malfunction is 
suspected. Refer to GROUP 00, How to Use 
Troubleshooting/Inspection Service Points 

− How to 

Cope with Intermittent Malfunction 

P.00-6

.)

NO :  Replace the immobilizer-ECU.

IGNITION SWITCH

TSB Revision

CHASSIS ELECTRICAL

54A-20

INSPECTION PROCEDURE 3: Engine Cranks, but does not Start.

.

TECHNICAL DESCRIPTION
If the engine cranks, but does not start, an MFI sys-
tem problem may exist in addition to a malfunctioning 
immobilizer system. The engine will not start if the 
ignition key has not been properly registered.

.

TROUBLESHOOTING HINTS

• Malfunction of MFI system

• Malfunction of immobilizer-ECU 

.

DIAGNOSIS

Required Special Tools:

• MB991223: Harness Set

• MB991502: Scan Tool

STEP 1. Check the battery voltage.
Measure the battery voltage during cranking.
Q: Is the voltage 8 volts or more?

YES : Go to Step 2.
NO :  Check the condition of the battery. Refer to 

P.54A-4

.

STEP 2. Check for DTCs.
Q: Have any DTCs set?

Yes :  Go to Step 3.
No :  Go to Step 5.

STEP 3. Check for immobilizer system DTCs.
Q: Have any immobilizer system DTCs set?

Yes :   Refer to 

P.54A-8

.

No :  Go to Step 4.

STEP 4. Check for MFI system DTCs.
Q: Have any MFI system DTCs set?

Yes :  Refer to GROUP 13A, Diagnosis 

P.13Ab-22

.

No :  Go to Step 5.

STEP 5. Attempt to start the engine.
Q: Does the engine start?

YES : The procedure is complete (If no malfunctions are 

found in all steps, an intermittent malfunction is 
suspected. Refer to GROUP 00, How to Use 
Troubleshooting/Inspection Service Points-How to 
Cope with Intermittent Malfunction 

P.00-6

).

NO :  Refer to GROUP 13A, Diagnosis 

− Symptom Chart 

P.13Ab-26

. If the malfunction is not resolved, replace 

the immobilizer-ECU. Then register the password 
(secret code) and encrypted code. (Refer to 

P.54A-

22

.) The engine should now start.

IGNITION SWITCH

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CHASSIS ELECTRICAL

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DATA LIST REFERENCE TABLE

M1543007300143

CHECK AT IMMOBILIZER-ECU 

M1543007600230

TERMINAL VOLTAGE CHECK 

MUT-II
SCAN TOOL
DISPLAY

ITEM 
NO.

INSPECTION ITEM

INSPECTION
REQUIREMENT

NORMAL 
CONDITION

KEY REGISTERED

01

Key has been registered -

Number of registered ignition 
keys

ACX01564 AB

TERMINAL NO.

SIGNAL

CHECKING 
REQUIREMENT

TERMINAL VOLTAGE

3

Immobilizer-ECU ground Always

0V

5

powertrain control 
module

-

-

7

Immobilizer-ECU power 
supply

Ignition switch: "LOCK" 
(OFF) 

0V

Ignition switch: "ON" 

Battery positive voltage

10

Ignition key ring antenna -

-

11

Ignition key ring antenna -

-

IGNITION SWITCH

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CHASSIS ELECTRICAL

54A-22

SPECIAL TOOLS

M1543000600411

ON-VEHICLE SERVICE

ENCRYPTED CODE REGISTRATION METHOD

M1543008100205

Required Special Tool:

• MB991502: Scan Tool (MUT-II)

CAUTION

Because registering the encrypted codes is done after all 
previously-registered codes have been erased, you should 
keep all of the ignition keys that have already been regis-
tered accessible.
If the ignition key, Immobilizer-ECU, powertrain control module 
is replaced or an ignition key is added, encrypted codes of all 
the ignition keys must be registered. (A maximum of eight dif-
ferent ignition key can be registered.) Moreover, when the 
immobilizer-ECU has been replaced, you will need to use scan 
tool MB991502 to register the immobilizer-ECU and input the 
vehicle secret code and to register the password (secret code) 
that the owner specifies into the immobilizer-ECU.

TOOL

TOOL NUMBER 
AND NAME

SUPERSESSION

APPLICATION

MB991502 Scan tool 
(MUT-II)

MB991496-OD

• Immobilizer system 

check

• Encrypted code 

registration

MB991223
A: MB991219
B: MB991220 
C: MB991221
D: MB991222
Harness set
A: Test harness
B: LED harness
C: LED harness 

adapter

D: Probe

MB991223

Making voltage and 
resistance measurements 
during troubleshooting

A: Connect pin contact 

pressure inspection

B: Power circuit 

inspection

C: Power circuit 

inspection

D: Commercial tester 

connection

B991502

MB991223

A

B

C

D

AC