Mitsubishi Evolution X. Manual - part 586

DIAGNOSIS

TSB Revision

KEYLESS OPERATION SYSTEM (KOS)

42B-251

STEP 3. Using scan tool MB991958, check pulse check.
Check the signals related to the keyless entry system opera-
tion.

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. Refer to "How to connect the 

Scan Tool (M.U.T.-III) 

P.42B-10

."

(2) Confirm the ETACS pulse check.

• Remove the ignition key from the ignition key cylinder.

OK: The scan tool (M.U.T.-III) tone alarm sounds.

Q: Is the check result normal?

YES : Go to Step 4.
NO :  Refer to "Signals from transmitter switches are not 

received 

P.42B-260

."

STEP 4. Check trunk lid latch connector F-19 and 
ETACS-ECU connector C-311 for loose, corroded or 
damaged terminals, or terminals pushed back in the 
connector.
Q: Is trunk lid latch connector F-19 and ETACS-ECU 

connector C-311 in good condition?
YES : Go to Step 5.
NO :  Repair or replace the damaged component(s). Refer 

to GROUP 00E, Harness Connector Inspection 

P.00E-2

.

Item name

Conditions

Transmitter switch

Turn the switch ON/OFF.

AC608435

Data link connector

MB991827

MB991824

MB991910

AB

DIAGNOSIS

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KEYLESS OPERATION SYSTEM (KOS)

42B-252

STEP 5. Check the trunk lid latch assembly.
Remove the trunk lid latch assembly. Refer to GROUP 42A, 
Trunk lid removal and installation 

P.42A-147

.

Q: Is the trunk lid actuator normal?

YES : Go to Step 6.
NO :  Replace the trunk lid latch assembly.

STEP 6. Check the ground circuit to the trunk lid lock 
actuator. Measure the resistance at trunk lid lock actuator 
connector F-19.
(1) Disconnect trunk lid lock actuator connector F-19 and 

measure the resistance available at the wiring harness side 
of the connector.

(2) Measure the resistance value between terminal 2 and 

ground.

• The resistance should be 2 ohms or less.

Q: Is the measured resistance 2 ohms or less?

YES : Go to Step 9.
NO :  Go to Step 7.

Lever position

Battery 
connection

Lever operation

At the "OFF" 
position

• Connect 

terminal No.2 
and the 
negative 
battery 
terminal.

• Connect 

terminal No.3 
and the 
positive battery 
terminal.

The lever moves 
from the "OFF" 
position to the 
"OPEN" position.

AC609215

AB

Off

Lever

Open

AC209731

Connector F-19
(harness side)

AC208731CD

DIAGNOSIS

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KEYLESS OPERATION SYSTEM (KOS)

42B-253

STEP 7. Check the wiring harness between the trunk lid 
latch connector F-19 (terminal No. 2) and the ground for 
open circuit.
(1) Disconnect trunk lid latch connector F-19 and ground, and 

check the wiring harness.

(2) Check the wiring harness between trunk lid latch connector 

F-19 (terminal No. 2) and ground.

OK: Continuity exists (2 

Ω or less)

Q: Is the wiring harness between trunk lid latch connector 

F-19 (terminal No. 2) and ground in good condition?
YES  : Go to Step 8.
NO (trunk lid latch connector F-19 terminal No. 2 

− 

ground.) : Repair the wiring harness between trunk lid latch 

connector F-19 (terminal No. 2) and ground.

STEP 8. Check the wiring harness between the trunk lid 
latch connector F-19 (terminal No. 2) and the ground for 
short circuit.
(1) Disconnect unlock sensor (front door: RH) connector E-05, 

and check the wiring harness.

(2) Check the wiring harness between trunk lid latch connector 

F-19 (terminal No. 2) and ground

OK: No continuity

Q: Is the wiring harness between trunk lid latch connector 

F-19 (terminal No. 2) and the ground in good condition?
YES  : Go to Step 11.
NO (trunk lid latch connector F-19 terminal No. 2 

− 

ground.) : Repair the wiring harness between trunk lid latch 

connector F-19 (terminal No. 2) and ground.

STEP 9. Check the wiring harness between the trunk lid 
latch connector F-19 (terminal No. 3) and the ETACS-ECU 
connector C-311 (terminal No. 1) for open circuit.
(1) Disconnect trunk lid latch connector F-19 and ETACS-ECU 

connector C-311, and check the wiring harness.

(2) Check the wiring harness between trunk lid latch connector 

F-19 (terminal No. 3) and ETACS-ECU connector C-311 
(terminal No. 1).

OK: Continuity exists (2 

Ω or less)

Q: Is the wiring harness between trunk lid latch connector 

F-19 (terminal No. 3) and ETACS-ECU connector C-311 
(terminal No. 1) in good condition?
YES  : Go to Step 10.
NO (trunk lid latch connector F-19 terminal No. 3 

− 

ETACS-ECU connector C-311 terminal No. 1.) : Repair 

the wiring harness between trunk lid latch connector 
F-19 (terminal No. 3) and ETACS-ECU connector 
C-311 (terminal No. 1).

AC209731

Connector F-19
(harness side)

AC208731CD

AC209731

Connector F-19
(harness side)

AC208731CD

AC709707HP

Harness side: F-19

Harness side: C-311

DIAGNOSIS

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KEYLESS OPERATION SYSTEM (KOS)

42B-254

STEP 10. Check the wiring harness between the trunk lid 
latch connector F-19 (terminal No. 3) and the ground for 
short circuit.
(1) Disconnect trunk lid latch connector F-19, and check the 

wiring harness.

(2) Check the wiring harness between trunk lid latch connector 

F-19 (terminal No. 3) and ground

OK: No continuity

Q: Is the wiring harness between trunk lid latch connector 

F-19 (terminal No. 3) and the ground in good condition?
YES  : Go to Step 11.
NO (trunk lid latch connector F-19 terminal No. 3 

− 

ground.) : Repair the wiring harness between trunk lid latch 

connector F-19 (terminal No. 3) and ground.

STEP 11. Check of the troubles
Operate the transmitter and check that the trunk lid can be 
opened.
Q: Is the check result normal?

YES : The diagnosis is complete.
NO :  Replace the ETACS-ECU. When the ETACS-ECU is 

replaced, register the keyless ID. Refer to 

P.42C-114

. 

The trunk lid can be opened by means of the 
transmitter.

AC209731

Connector F-19
(harness side)

AC208731CK