Mitsubishi Montero (2004+). Manual - part 515

IGNITION SWITCH

TSB Revision

CHASSIS ELECTRICAL

54A-29

ON-VEHICLE SERVICE

ENCRYPTED CODE REGISTRATION METHOD

M1543008100465

Required Special Tools:

• MB991958: Scan Tool (MUT-III Sub Assembly)

• MB991824: Vehicle Communication Interface (V.C.I.)

• MB991827: MUT-III USB Cable

• MB991911: MUT-III Main Harness B

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 MB991958 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.
If an attempt is made to start the engine with an unregistered 
ignition key, cranking occurs, but fuel supply is cut off to disable 
the engine. In approx. 10 seconds, the theft-alarm indicator will 
blink for approx. 30 seconds.
NOTE: powertrain control module has an encrypted code for 
immobilizer-ECU, and the encrypted code is registered in the 
immobilizer-ECU and ignition key.

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

TOOL

TOOL NUMBER 
AND NAME

SUPERSESSION

APPLICATION

MB991223

A

B

C

D

AC

ACX02297

THEFT ALARM 

INDICATOR LIGHT

DEFROSTER NOZZLE

AC

IGNITION SWITCH

TSB Revision

CHASSIS ELECTRICAL

54A-30

POINTS TO NOTE DURING OPERATION

If none of the functions can be used, check the diagnostic trou-
ble codes, and after carrying out any necessary repairs, repeat 
the operation. If an incorrect password is input five times in a 
row, the immobilizer-ECU judges that an unauthorized opera-
tion is being attempted. Start-prevention mode will be set, and 
engine operation will stop and all special functions will be dis-
abled. If the ignition switch is turned to "ON" position and left in 
that position for approximately 20 minutes, "Unauthorized oper-
ation, start- prevention mode" will be cancelled.

KEY ID REGISTER

All ignition keys can be registered with scan tool MB991958. 
Additional ignition keys can be registered with or without scan 
tool MB991958.

.

Registration with scan tool

CAUTION

To prevent damage to scan tool MB991958, always turn the 
ignition switch to "LOCK" (OFF) position before connect-
ing or disconnecting scan tool MB991958.
NOTE: 

.

•

Before registration, check that no DTC code is set. If a DTC 
code is set, resolve the problem beforehand.

•

Using the key ID register function will cause all key IDs that 
have been previously registered in the immobilizer-ECU to 
be erased. All keys need to be registered. Those which 
have been registered before should be on hand before 
using this function.

•

If registering more than one key, do not disconnect scan 
tool MB991958 halfway through the registration process.

•

After registering key IDs, check that the engine can be 
started using all of the keys that have been registered. If the 
engine will not start, refer to Immobilizer System Diagnosis 

P.54A-8

.

IGNITION SWITCH

TSB Revision

CHASSIS ELECTRICAL

54A-31

1. Connect scan tool MB991958 to the data link connector.
2. Turn the ignition switch to "ON" position.
3. Select "Interactive Diagnosis" from the start-up screen.

4. Select "System select."

5. Choose "IMMOBILIZER" from the "POWER TRAIN" tab.

6. Choose "Special Function" from "IMMOBILIZER" screen.

AC306409AF

MB991911

MB991824

MB991827

System select

Special function

CAN bus diagnosis

Function Select Menu

Menu

AC209666

Maintenance

AC

MFI

ELC-A/T

IMMOBILIZER

SS4II

CRUISE CNTRL

CHASSIS

BODY

System Select Menu

POWER TRAIN

AC209667

AC

Check Chart For

 Problem Sy

Data List

Special 

Function

Self-diagnosis

Voltmeter

Simulated Vehicle 

Speed Out

Drive Recorder

Resistor

POWERTRAIN

IMMOBILIZER

IMMOBILIZER

AC207298

AD

IGNITION SWITCH

TSB Revision

CHASSIS ELECTRICAL

54A-32

7. Choose "Key registration" from "Special Function" screen.

8. Enter the vehicle’s password (secret code) on the "Key 

registration" screen, and then click the check mark icon. 
Follow the prompts on the screen to insert key(s) into the 
ignition switch to begin key registration.

9. If the key ID was registered successfully, "Progress" 

indication will turn active (gray). Then the registration 
process completes. If the key ID failed to be registered, 
"In-Complete" indication will turn active (gray).

10.The number of keys currently registered will be displayed. 

To register an additional key, replace the ignition key with 
the next key to be registered within five seconds. Key ID 
registration screen will be displayed, then register another 
key.
NOTE: A maximum of eight different keys can be registered.

11.This completes the registration operation. Turn the ignition 

switch "LOCK" (OFF) and leave it off for approximately ten 
seconds.

12.Check that the engine can be started with each of the 

ignition keys.

13.Check that the immobilizer system DTC and MFI system 

DTC did not set.

14.If no DTC is shown, terminate scan tool MB991958.
15.Turn the ignition switch to "LOCK" (OFF) position.
16.Disconnect scan tool MB991958.

.

Registration of additional keys with scan tool
Additional key(s) can be registered with scan tool while keeping 
all existing key data.

CAUTION

To prevent damage to scan tool MB991958, always turn the 
ignition switch to "LOCK" (OFF) position before connect-
ing or disconnecting scan tool MB991958.
NOTE: To register additional keys with scan tool, no registered 
keys must be lost.

Key registration

Transponder ID 

addition

POWERTRAIN

Special Function

IMMOBILIZER

Special Function

AC207299

AE

POWERTRAIN

IMMOBILIZER

Special Function

7

8

9

4

5

6

1

2

3

0

Back

Back

Space

Space

Clear

Clear

Key registration

AC207300

AC

POWERTRAIN

IMMOBILIZER

Special Function

IMMOBILIZER-ECU registration

Progress

In-Complete

Key registration

AC207302

AC