Mitsubishi Montero (2002-2004). Manual — part 459

IGNITION SWITCH

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CHASSIS ELECTRICAL

54A-7

IGNITION SWITCH

GENERAL DESCRIPTION

M1543009901014

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Ignition key reminder tone alarm
The ignition key reminder tone alarm will sound
under the following condition, and warn the driver to
remove the ignition key.

• The driver's door is opened when the ignition

switch is at "LOCK" (OFF) or "ACC" position with-
out removing the ignition key.

However, the light reminder tone alarm will take pre-
cedence over this function.

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Immobilizer system
The immobilizer system consists of the ignition key,
the key ring antenna, the immobilizer-ECU, and the
PCM. The ignition key has a built-in transponder. The
key ring antenna is installed on the steering lock key
cylinder. Only the registered ignition key permits the
engine to start, therefore, the engine can never be
started by means of a forged key or by connecting
the ignition wiring directly. The system is significantly
safe and reliable against theft. In addition, the driver
has only to turn the ignition switch to the "ON" posi-
tion to activate the immobilizer system. If the require-
ments for starting the engine are not satisfied, the
engine will be immobilized. If the ignition key is lost
or another ignition key is added, the encrypted code
can be registered or erased by using scan tool.

IGNITION KEY REMINDER TORN ALARM DIAGNOSIS

M1543000700678

The Ignition key reminder tone alarms is controlled
by the Simplified Wiring System (SWS). For trouble-
shooting, refer to GROUP 54B, SWS Diagnosis

P.54Bb-2

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IMMOBILIZER SYSTEM DIAGNOSIS

INTRODUCTION TO IMMOBILIZER SYSTEM DIAGNOSIS

M1543009901025

CAUTION

The encrypted code should always be re-regis-
tered when replacing the immobilizer-ECU.
The immobilizer system consists of the immobilizer-
ECU, PCM, ignition key and ignition key ring
antenna. If the engine cannot be started by using a
registered ignition key, one of these components
may be defective. If the immobilizer system has
immobilized the engine, MFI system DTC P1610 will
be output. In this case, observe the immobilizer sys-
tem troubleshooting.

IMMOBILIZER SYSTEM DIAGNOSTIC TROUBLESHOOTING STRATEGY

M1543006900539

Use the following steps to plan your diagnostic strat-
egy.
1. Gather information about the problem from the

customer.

2. Verify that the condition as described by the

customer exists.

3. Check the vehicle for any immobilizer system

DTCs.

4. If you cannot verify the condition and there are no

immobilizer system DTCs, the malfunction is
intermittent. Refer to GROUP 00, How to Use
Troubleshooting/inspection Service Points

− How

to Cope with Intermittent Malfunctions

P.00E-6

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5. If you can verify the condition but there are no

immobilizer system DTCs, or the system cannot
communicate with scan tool MB991502, refer to
Symptom Chart and find the fault

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IGNITION SWITCH

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CHASSIS ELECTRICAL

54A-8

6. If there is an immobilizer system DTC, record the

DTC, then erase it from the memory using scan
tool MBB991502.

7. Recreate the immobilizer system DTC set

conditions to see if the same immobilizer system
DTC will resets.

(1) If the same immobilize system DTC resets,

perform the appropriate diagnostic procedure.
Refer to Diagnostic Trouble Code Chart

P.54A-8

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(2) If the same immobilizer system DTC does not

reset, the malfunction is intermittent. Refer to
GROUP 00, How to Use Troubleshooting/
inspection Service Points

− How to Cope with

Intermittent Malfunctions

P.00-6

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IMMOBILIZER SYSTEM TROUBLE CODE
DIAGNOSIS

M1543007000283

Retrieving and Erasing Immobilizer System
Diagnostic Trouble Codes

Required Special Tool:

• MB991502: Scan Tool (MUT-II)

CAUTION

Always turn the ignition switch to "LOCK" (OFF) position
before connecting or disconnecting scan tool MB991502.
1. Connect scan tool MB991502 to data link connector (16-

pin).

2. Turn the ignition switch to "ON" position.
3. Use scan tool MB991502 to check or erase immobilizer

system DTCs.

4. Turn the ignition switch to "LOCK" (OFF) position.
5. Disconnect scan tool MB991502.

DIAGNOSTIC TROUBLE CODE CHART

M1543007100291

Use the following chart to develop proper diagnostic
strategy.

ACX01539

16-pin

MB991502

AI

DIAGNOSTIC
TROUBLE CODE NO.

DESCRIPTION

REFERENCE PAGE

11

Transponder communication system or radio interference
of encrypted code

P.54A-9

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12

Encrypted codes are not the same or are not registered

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DIAGNOSTIC TROUBLE CODE PROCEDURES

DTC 11: Transponder Communication System or Radio Interference of Encrypted Code

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CIRCUIT OPERATION
The ignition key is powered by the ignition key ring
antenna. The ignition key then sends an encrypted
code. The ignition key ring antenna receives the
encrypted code, and determines if the ignition key is
registered.

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DTC SET CONDITION

• DTC 11 may be output if other ignition keys are in

the vicinity of the vehicle as it is being started.

• The transponder’s encrypted code is not sent to

the immobilizer-ECU immediately after the igni-
tion switch is turned to "ON" position.

NOTE: DTC 11 is always output together with MFI
system DTC P1610.

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TROUBLESHOOTING HINTS

• Radio interference of the encrypted code

• Malfunction of the transponder

• Malfunction of the ignition key ring antenna

• Malfunction of the immobilizer-ECU

• Damaged wiring harness of connectors

AC205535AB

Ignition Key Ring Antenna Circuit

AC204170

CONNECTOR : D-121

DN

AC204172

CONNECTOR : D-201

AJ

IGNITION SWITCH

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DIAGNOSIS

Required Special Tools:

• MB991223: Harness Set

• MB991502: Scan Tool (MUT-II)

STEP 1. Check for presence of other key near the key in
the ignition.
Q: Is there any other key near the key in the ignition?

YES : Move the other key well away from key being used.

Retest the system.

NO : Go to Step 2.

STEP 2. Check that the engine start using the spare
ignition key which encrypted code has been registered.
Q: Does the engine start using the spare ignition key for

which the encrypted code has been registered?
YES : replace the ignition key that does not work. Then

register the password (secret code) and encrypted
code

P.00E-2

. Retest the system.

NO : Go to Step 3.

STEP 3. Check that DTC is output, DTC 11 or 12?
Q: Which DTC is output, DTC 11 or 12?

DTC12 is output : Refer to DTC 12

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DTC11 is output : Go to Step 4.

STEP 4. Check the ignition key ring antenna by
backprobing.
Do not disconnect the ignition key ring antenna connector D-
201 and check the resistance on the harness side connector
between terminal number 1 and terminal number 2 by
backprobing.
Q: Is the resistance less than 2 ohms?

YES : Go to Step 5.
NO : Replace the ignition key ring antenna. Retest the

system.

ACX01679AC

CONNECTOR: D - 201

1 2