Mitsubishi Montero (2004+). Manual - part 738

SYMPTOM PROCEDURES

TSB Revision

SIMPLIFIED WIRING SYSTEM (SWS)

54B-209

STEP 5. Verify the hazard warning light.
Q:  Do the hazard warning lights work normally?

YES : Replace the ETACS-ECU. Verify that the answerback 

functions work normally.

NO :  Refer to Inspection Procedure K-2 "Hazard warning 

lights do not illuminate 

P.54B-379

."

INSPECTION PROCEDURE E-3: Keyless Entry System: Encrypted code cannot be registered

.

CIRCUIT OPERATION
The ETACS-ECU operates the encrypted code regis-
ter mode according to the following signals:

• Key reminder switch

• Hazard warning light switch

.

TECHNICAL DESCRIPTION (COMMENT)
If the encrypted code register mode can not be set, 
the input circuits from the key reminder switch, haz-
ard warning light switch or the ETACS-ECU may be 
defective.

If the encrypted code register mode can be set but 
the transmitter can not be registered, the transmitter 
or the ETACS-ECU may be defective.

.

TROUBLESHOOTING HINTS

• The key reminder switch may be defective

• The hazard warning light switch may be defective

• The transmitter may be defective

• The ETACS-ECU may be defective

• The wiring harness may be damaged or the con-

nector(s) may have loose, corroded or damaged 
terminals, or terminals pushed back in the con-
nector

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

Encrypted Transmitter Code Circuit

SYMPTOM PROCEDURES

TSB Revision

SIMPLIFIED WIRING SYSTEM (SWS)

54B-210

STEP 1. Verify the trouble symptom.
Q: Can the encrypted code register mode be set?

YES : Refer to Inspection Procedure P-10 "ETACS-ECU 

does not receive a signal from the lock, unlock switch 
or panic switch 

P.54B-626

."

NO :  Go to Step 2.

STEP 2. Check the input signal (by using the pulse check 
mode of the monitor.)
Check the input signals from the following switches:

• Key reminder switch

• Hazard warning light switch

CAUTION

To prevent damage to scan tool MB991958, always turn the 
ignition switch to the "LOCK" (OFF) position before con-
necting or disconnecting scan tool MB991958.
(1) Connect scan tool MB991958 to the data link connector.
(2) Operate scan tool MB991958 as follows:

1. Select "SYSTEM SELECT."
2. Select "SWS."
3. Select "PULSE CHECK."

(3) Verify scan tool MB991958 sounds or not.
(4) If the switches (see table below), which are applicable for 

the input signal check, are operated.

Q: When the key reminder switch and the hazard warning 

light switch are operated, does scan tool MB991958 
sound?
Buzzer of scan tool MB991958 sounds normally : 

Replace the ETACS-ECU. Verify that the encrypted 
code can be registered in the transmitter.

Scan tool MB991958 does not sound when the ignition 
key is removed and reinserted : Refer to Inspection 

Procedure P-1 "ETACS-ECU does not receive a 
signal from the key reminder switch 

P.54B-545

."

Scan tool MB991958 does not sound when the hazard 
warning light switch is turned from "OFF" to "ON" : 

Refer to Inspection Procedure P-2 "ETACS-ECU does 
not receive a signal from the hazard warning light 
switch 

P.54B-549

."

ITEM NAME

CHECK CONDITIONS

Key reminder switch Insert and remove the ignition key

Hazard warning 
light switch

Turn the hazard warning light switch 
from the "OFF" to "ON" position.

AC307591 AB

MB991911

DATA LINK

CONNECTOR

MB991824

MB991827

SYMPTOM PROCEDURES

TSB Revision

SIMPLIFIED WIRING SYSTEM (SWS)

54B-211

SUNROOF

GENERAL DESCRIPTION CONCERNING THE SUNROOF

M1549021200074

The following ECUs affect the functions and control 
of the sunroof.

Sunroof timer function
After the ignition switch is turned OFF, the system continues to 
turn ON the sunroof relay for about 30 seconds and to enable 
the opening and closing of the sunroof by the sunroof switch. 
When the driver's or front passenger’s door is opened while the 
timer is in operation, the sunroof relay will be turned OFF and 
the sunroof timer function will be finished. As for the sunroof 
functions, refer to GROUP 42 

− Sunroof 

P.42-63

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FUNCTION

CONTROL ECU

Sunroof timer function

ETACS-ECU, sunroof motor assembly

AC005433AG

ON

OFF

ON

OFF

ON 

(OPEN)

OFF 

(CLOSED)

IGNITION 

SWITCH (IG1)

SUNROOF RELAY

DOOR SWITCH

t

t: 30 seconds

t

SYMPTOM PROCEDURES

TSB Revision

SIMPLIFIED WIRING SYSTEM (SWS)

54B-212

General circuit diagram regarding the sunroof