Mitsubishi Outlander (2013+). Manual - part 544

TROUBLESHOOTING <KOS-ECU>

KEYLESS OPERATION SYSTEM (KOS)

42B-37

STEP 3. M.U.T.-III diagnosis code
Check if any diagnosis code is set to the KOS-ECU.

Q: Is the diagnosis code set?

YES : 

Refer to 

P.42B-11

.

NO : 

Go to Step 4.

STEP 4. Retest the system
Check that the keyless operation warning lamp turns 
OFF unless the flashing or illumination conditions are 
met.

Q: Is the check result normal?

YES : 

Intermittent malfunction is suspected (Refer 

to GROUP 00 

− How to Use 

Troubleshooting/Inspection Service Points 

− 

How to Cope with Intermittent Malfunction ).

NO : 

Replace KOS-ECU and register the ID 
codes (Refer to 

P.42B-88

).

Inspection Procedure 5: No door will be locked or unlocked by operating a lock/unlock switch on any 
door.

CAUTION

Before replacing the ECU, ensure that the power 
supply circuit, the earth circuit and the communi-
cation circuit are normal.

PROBABLE CAUSES

• Malfunction of the CAN bus lines

• Malfunction of the central door locking system

• Malfunction of the keyless operation key

• Damaged wiring harness and connectors

• Malfunction of the KOS-ECU

• Function setting error or no setting with a custom-

isation

DIAGNOSIS PROCEDURE

STEP 1. M.U.T.-III CAN bus diagnostics
Use M.U.T.-III to diagnose the CAN bus lines.

Q: Is the check result normal?

YES : 

Go to Step 2.

NO : 

Repair the CAN bus line (Refer to GROUP 
54C 

− Troubleshooting ).

STEP 2. M.U.T.-III diagnosis code
Check if any diagnosis code is set to the KOS-ECU.

Q: Is the diagnosis code set?

YES : 

 Refer to diagnosis code chart 

P.42B-11

.

NO : 

Go to Step 3.

STEP 3. Check the central door locking system 
operation
Check that the central door locking system works 
normally.

Q: Is the check result normal?

YES : 

Go to Step 4.

NO : 

Perform troubleshooting for the central door 
locking system (Refer to GROUP 42A 

− 

Troubleshooting ).

STEP 4. Check the customisation
Check that "KOS feature" is set to "Both enable" with 
a customisation function.

Q: Is it set to "Both enable"?

YES : 

Go to Step 5.

NO : 

Set "KOS feature" to "Both enable" with a 
customisation function (Refer to 

P.42B-90

).

STEP 5. Check with another registered keyless 
operation key.

Q: Can the engine switch be turned ON? (Is the 

keyless operation key recognised?)
YES : 

Replace the keyless operation key that 

could not turn the engine switch ON (the 
keyless operation key was not recognised), 
and register the ID codes (refer to 

P.42B-88

).

NO : 

Go to Step 6.

STEP 6. Check of the troubles
Operate the lock/unlock switch to check that the door 
can be locked and unlocked.

Q: Is the check result normal?

YES : 

The diagnosis is complete.

NO : 

Replace KOS-ECU and register the ID 
codes (Refer to 

P.42B-88

).

TROUBLESHOOTING <KOS-ECU>

KEYLESS OPERATION SYSTEM (KOS)

42B-38

Inspection Procedure 6: Driver's door lock/unlock switch does not work.

CAUTION

Before replacing the ECU, ensure that the power 
supply circuit, the earth circuit and the communi-
cation circuit are normal.

PROBABLE CAUSES

• Malfunction of the outside transmission antenna 

assembly (driver's side)

• Malfunction of the lock/unlock switch (driver's 

side)

• Damaged wiring harness and connectors

• Malfunction of the KOS-ECU

DIAGNOSIS PROCEDURE

STEP 1. M.U.T.-III diagnosis code
Check if any diagnosis code is set to the KOS-ECU.

Q: Is the diagnosis code set?

YES : 

 Refer to diagnosis code chart 

P.42B-11

.

NO : 

Go to Step 2.

STEP 2. Lock/unlock switch (LH) check
Check that the lock/unlock switch (LH) is normal 
(Refer to GROUP 42A 

− Inspection ).

Q: Is the check result normal?

YES : 

Go to Step 3.

NO : 

Replace the lock/unlock switch (LH).

STEP 3. Resistance measurement at lock/unlock 
switch (LH) connector (earth line)
(1) Disconnect the connector, and measure at the 

wiring harness side.

(2) Measure the resistance between the lock/unlock 

switch (LH) connector (earth line) and body earth.

OK: Continuity exists (2 

Ω or less)

Q: Is the check result normal?

YES : 

Go to Step 5.

NO : 

Go to Step 4.

STEP 4. Check of open circuit in earth line 
between the lock/unlock switch (LH) connector 
and the body earth.

NOTE: Before the wiring harness check, check the 
intermediate connectors, and repair if necessary.

Q: Is the check result normal?

YES : 

Go to Step 6.

NO : 

Repair the wiring harness.

STEP 5. Check of short to power supply, short to 
earth, and open circuit in DRRQ line between the 
KOS-ECU connector and the lock/unlock switch 
(LH) connector.

NOTE: Before the wiring harness check, check the 
intermediate connectors, and repair if necessary.

Q: Is the check result normal?

YES : 

Go to Step 6.

NO : 

Repair the wiring harness.

STEP 6. KOS communication test
Using M.U.T-III, perform the antenna communication 
test to check that the outside transmission antenna 
assembly (driver's side) communicates normally 
(Refer to 

P.42B-89

).

Q: Is the check result normal?

YES : 

Go to Step 7.

NO : 

Perform troubleshooting for the diagnosis 
code No. B240A (Refer to 

P.42B-11

).

STEP 7. Check of the troubles
Operate the lock/unlock switch (LH) and check that 
the doors can be locked and unlocked.

Q: Is the check result normal?

YES : 

Intermittent malfunction is suspected (Refer 

to GROUP 00 

− How to Use 

Troubleshooting/Inspection Service Points 

− 

How to Deal with Intermittent Malfunction ).

NO : 

Replace KOS-ECU and register the ID 
codes (Refer to 

P.42B-88

).

Inspection Procedure 7: Front passenger's door lock/unlock switch does not work.

CAUTION

Before replacing the ECU, ensure that the power 
supply circuit, the earth circuit and the communi-
cation circuit are normal.

PROBABLE CAUSES

• Malfunction of the outside transmission antenna 

assembly (passenger's side)

TROUBLESHOOTING <KOS-ECU>

KEYLESS OPERATION SYSTEM (KOS)

42B-39

• Malfunction of the lock/unlock switch (passen-

ger's side)

• Damaged wiring harness and connectors

• Malfunction of the KOS-ECU

DIAGNOSIS PROCEDURE

STEP 1. M.U.T.-III diagnosis code
Check if any diagnosis code is set to the KOS-ECU.

Q: Is the diagnosis code set?

YES : 

 Refer to diagnosis code chart 

P.42B-11

.

NO : 

Go to Step 2.

STEP 2. lock/unlock switch (RH) check
Check that the lock/unlock switch (RH) is normal 
(Refer to GROUP 42A 

− Door Handle and Latch ).

Q: Is the check result normal?

YES : 

Go to Step 3.

NO : 

Replace the lock/unlock switch (RH).

STEP 3. Resistance measurement at lock/unlock 
switch (RH) connector (earth line)
(1) Disconnect the connector, and measure at the 

wiring harness side.

(2) Measure the resistance between the lock/unlock 

switch (RH) connector (earth line) and body 
earth.

OK: Continuity exists (2 

Ω or less)

Q: Is the check result normal?

YES : 

Go to Step 5.

NO : 

Go to Step 4.

STEP 4. Check of open circuit in earth line 
between the lock/unlock switch (RH) connector 
and the body earth.

NOTE: Before the wiring harness check, check the 
intermediate connectors, and repair if necessary.

Q: Is the check result normal?

YES : 

Go to Step 6.

NO : 

Repair the wiring harness.

STEP 5. Check of short to power supply, short to 
earth, and open circuit in ASRQ line between the 
KOS-ECU connector and the lock/unlock switch 
(RH) connector.

NOTE: Before the wiring harness check, check the 
intermediate connectors, and repair if necessary.

Q: Is the check result normal?

YES : 

Go to Step 6.

NO : 

Repair the wiring harness.

STEP 6. KOS communication test
Using M.U.T.-III, perform the antenna communication 
test to check that the outside transmission antenna 
assembly (passenger's side) communicates normally 
(Refer to 

P.42B-89

).

Q: Is the check result normal?

YES : 

Go to Step 7.

NO : 

Perform troubleshooting for the diagnosis 
code No. B240B (Refer to 

P.42B-11

).

STEP 7. Check of the troubles
Operate the lock/unlock switch (RH) to check that the 
doors can be locked and unlocked. 

Q: Is the check result normal?

YES : 

Intermittent malfunction is suspected (Refer 

to GROUP 00 

− How to Use 

Troubleshooting/Inspection Service Points 

− 

How to Deal with Intermittent Malfunction ).

NO : 

Replace KOS-ECU and register the ID 
codes (Refer to 

P.42B-88

).

Inspection Procedure 8: The lock switch and open switch of the tailgate lock release handle do not 
work.

CAUTION

Before replacing the ECU, ensure that the power 
supply circuit, the earth circuit and the communi-
cation circuit are normal.

PROBABLE CAUSES

• Malfunction of the outside transmission antenna 

assembly (tailgate)

• Malfunction of the tailgate lock release handle

• Damaged wiring harness and connectors

• Malfunction of the KOS-ECU

TROUBLESHOOTING <KOS-ECU>

KEYLESS OPERATION SYSTEM (KOS)

42B-40

DIAGNOSIS PROCEDURE

STEP 1. M.U.T.-III diagnosis code
Check if any diagnosis code is set to the KOS-ECU.

Q: Is the diagnosis code set?

YES : 

 Refer to diagnosis code chart 

P.42B-11

.

NO : 

Go to Step 2.

STEP 2. Tailgate lock release handle (lock switch 
and open switch) check
Check that the tailgate lock release handle (lock 
switch and open switch) is normal (Refer to GROUP 
42A 

− Tailgate Handle and Latch  <Vehicles without 

electric tailgate> or  <Vehicles with electric tailgate>).

Q: Is the check result normal?

YES : 

Go to Step 3.

NO : 

Replace the tailgate lock release handle.

STEP 3. Check of open circuit in earth line 
between the tailgate lock release handle 
connector and the body earth.

NOTE: Before the wiring harness check, check the 
intermediate connector, and repair if necessary.

Q: Is the check result normal?

YES : 

Go to Step 4.

NO : 

Repair the wiring harness.

STEP 4. KOS communication test
Using M.U.T-III, perform the antenna communication 
test to check that the outside transmission antenna 
assembly (tailgate) communicates normally (Refer to 

P.42B-89

).

Q: Is the check result normal?

YES : 

Go to Step 5.

NO : 

Perform troubleshooting for the diagnosis 
code No. B240C (Refer to 

P.42B-11

).

STEP 5. Check of the troubles
Operate the tailgate lock release handle and check 
that the tailgate can be locked and opened.

Q: Is the check result normal?

YES : 

Intermittent malfunction is suspected (Refer 

to GROUP 00 

− How to Use 

Troubleshooting/Inspection Service Points 

− 

How to Deal with Intermittent Malfunction ).

NO : 

Replace KOS-ECU and register the ID 
codes (Refer to 

P.42B-88

).

Inspection Procedure 9: The lock switch of the tailgate lock release handle does not perform the 
locking operation.

CAUTION

Before replacing the ECU, ensure that the power 
supply circuit, the earth circuit and the communi-
cation circuit are normal.

PROBABLE CAUSES

• Malfunction of the outside transmission antenna 

assembly (tailgate)

• Malfunction of the tailgate lock release handle 

(lock switch)

• Damaged wiring harness and connectors

• Malfunction of the KOS-ECU

DIAGNOSIS PROCEDURE

STEP 1. M.U.T.-III diagnosis code
Check if any diagnosis code is set to the KOS-ECU.

Q: Is the diagnosis code set?

YES : 

 Refer to diagnosis code chart 

P.42B-11

.

NO : 

Go to Step 2.

STEP 2. Tailgate lock release handle (lock 
switch) check
Check that the tailgate lock release handle (lock 
switch) is normal (Refer to GROUP 42A 

− Tailgate 

Handle and Latch  <Vehicles without electric tail-
gate> or  <Vehicles with electric tailgate>).

Q: Is the check result normal?

YES : 

Go to Step 3.

NO : 

Replace the tailgate lock release handle.

STEP 3. Check of short to power supply, short to 
earth, and open circuit in GTRQ line between the 
KOS-ECU connector and the tailgate lock release 
handle connector.

NOTE: Before the wiring harness check, check the 
intermediate connector, and repair if necessary.

Q: Is the check result normal?

YES : 

Go to Step 4.

NO : 

Repair the wiring harness.