Mitsubishi Montero (2004+). Manual - part 513

IGNITION SWITCH

TSB Revision

CHASSIS ELECTRICAL

54A-21

STEP 5. Check the immobilizer-ECU ground circuit by 
backprobing.

(1) Do not disconnect immobilizer-ECU connector D-121. 

(2) Measure the resistance between terminal 3 and ground by 

backprobing.

Q: Is the resistance less than 2 ohms?

YES : Go to Step 7.
NO :  Go to Step 8.

STEP 6. Check immobilizer-ECU connector D-121 for 
loose, corroded or damaged terminals, or terminals 
pushed back in the connector.

Q: Is immobilizer-ECU connector D-121 in good condition?

YES : Go to Step 7.
NO :  Repair or replace it. Refer to GROUP 00E, Harness 

Connector Inspection 

P.00E-2

. Confirm that scan tool 

MB991958 communicates normally.

AC204170

CONNECTOR : D-121

CV

HARNESS SIDE

2

3

8 7

9

10

1
6

5

12

4

11

AC204738 EH

HARNESS SIDE: D-121

4

3

2
7 8 9 10 11

5

12

1

6

AC204170

CONNECTOR : D-121

CV

HARNESS SIDE

2

3

8 7

9

10

1
6

5

12

4

11

IGNITION SWITCH

TSB Revision

CHASSIS ELECTRICAL

54A-22

STEP 7. Check the harness wire between immobilizer-ECU 
connector D-121 (terminal 3) and ground.

NOTE: Also check intermediate connector D-30, check the 
wires. If intermediate connector D-30 is damaged, repair or 
replace it. Refer to GROUP 00E, Harness Connector Inspec-
tion 

P.00E-2

.

Q: Is the harness wire between immobilizer-ECU connector 

D-121 (terminal 3) and ground damaged?
YES : Repair it. Confirm that scan tool MB991958 

communicates normally.

NO :  There is no action to be taken.

AC204188

CONNECTORS : D-30, D-121

D-30

BP

D-30

D-121

D-121

9 10

8

6 7

31 32

30

29

18 19 20 21

5

4

2

1

3

27

26

24

23

25

12 13 14 15 16 17

28

11
22
33

HARNESS SIDE

2

3

8 7

9

10

1
6

5

12

4

11

IGNITION SWITCH

TSB Revision

CHASSIS ELECTRICAL

54A-23

STEP 8. Check the harness wires between 
immobilizer-ECU connector D-121 (terminal 5) and PCM 
connector D-134 (terminal 65).

Q: Are the harness wires between immobilizer-ECU 

connector D-121 (terminal 5) and PCM connector D-134 
(terminal 65) damaged?
YES : Repair them. Confirm that scan tool MB991958 

communicates normally.

NO :  Go to Step 9.

STEP 9. Replace the immobilizer-ECU or PCM.

Replace the immobilizer-ECU or PCM.
Q: Did the communication with scan tool become possible 

after replacing the immobilizer-ECU or the power train 
control module?
YES : Register the password (secret code) and encrypted 

code 

P.54A-29

. Confirm that scan tool MB991958 

communicates normally

NO :  Go to Step 10.

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.00-6

).

NO :  Replace the immobilizer-ECU or PCM.

AC204170

CONNECTOR : D-121

CV

HARNESS SIDE

2

3

8 7

9

10

1
6

5

12

4

11

AC204171

CONNECTOR: D-134

COMPONENT SIDE

D-134(GR)

D-134(GR)

AF

76

85

65

72

71

73
82

75

81

74

6364

66

70

69

68

67

78

87

79

8889

80

77

86

62

61

8384

IGNITION SWITCH

TSB Revision

CHASSIS ELECTRICAL

54A-24

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

• 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

STEP 1. Using scan tool MB991958, read the diagnostic 
trouble code.

CAUTION

To prevent damage to scan tool MB991958, always turn the 
ignition switch to "LOCK" (OFF) position before connect-
ing or disconnecting scan tool.
 Use scan tool MB991958 to check if DTC 11 is set.
(1) Connect scan tool MB991958 to the data link connector.
(2) Turn the ignition switch "ON" position.
(3) Read the immobilizer system diagnostic trouble code.
Q: Does DTC11 reset?

YES : Refer to 

P.54A-12

.

NO :  Replace the ignition key that cannot 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 

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.

AC306409AF

MB991911

MB991824

MB991827