Mitsubishi Galant (2004+). Manual - part 1443

IGNITION SWITCH

TSB Revision

CHASSIS ELECTRICAL

54A-15

DIAGNOSIS 

Required Special Tools:

• MB991958: Scan Tool (MUT-III Sub Assembly)

• MB991824: Vehicle Communication Interface (V.C.I.)

• MUT-III USB Cable

• MB991910: MUT-III Main Harness A (Vehicles with CAN 

communication system)

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.54A-40

. Retest the system.

NO :  Go to Step 3.

STEP 3. Recheck for diagnosis trouble code.

(1) Connect scan tool MB991958 to the data link connector.
(2) Turn the ignition switch to the "ON" position.

(3) Use scan tool MB991958 to check immobilizer system 

diagnostic trouble codes.

(4) Turn the ignition switch to  "LOCK"(OFF) position.
(5) Disconnect scan tool MB991958.
Q: Which DTC is output, DTC 11 or 12?

DTC12 is output : Refer to DTC 12 

P.54A-17

.

DTC11 is output : Go to Step 4.

AC305412

AB

MB991910

DATA LINK

CONNECTOR

MB991824

MB991827

IGNITION SWITCH

TSB Revision

CHASSIS ELECTRICAL

54A-16

STEP 4. Check the ignition key ring antenna.

(1) Disconnect the key reminder switch connector C-310.

(2) Measure the resistance value between terminal number 3 

and terminal number 7 by backprobing.

• The measured value should be 2 ohm or less.

Q: Is the check result normal?

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

system.

STEP 5. Check Immobilizer-ECU connector C-124 and key 
reminder switch connector C-310 for loose, corroded or 
damaged terminals, or terminals pushed back in the 
connector.

Q: Are immobilizer-ECU connector C-124 and key reminder 

switch connector C-310 in good condition?
YES : Go to Step 6.
NO :  Repair or replace the damage component(s). Confirm 

that scan tool MB991958 communicates normally.

AC305235AF

CONNECTOR: C-310

HARNESS SIDE

AC209364

CONNECTOR C-310 
(HARNESS SIDE)

JP

AC305231CQ

CONNECTOR: C-124

HARNESS SIDE

AC305235AF

CONNECTOR: C-310

HARNESS SIDE

IGNITION SWITCH

TSB Revision

CHASSIS ELECTRICAL

54A-17

STEP 6. Check the wiring harness between 
immobilizer-ECU connector C-124 (terminal 7 and 8) and 
key reminder switch connector C-310 (terminal 7 and 3).

Q: Are the wiring harness between immobilizer-ECU 

connector C-124 (terminal 7 and 8) and key reminder 
switch connector C-310 (terminal 7 and 3) in good 
condition?
YES : Replace the immobilizer-ECU and then register the 

password (secret code) and encrypted code (Refer to 

P.54A-40

). Retest the system.

NO :  Repair or replace the damaged component(s). 

Confirm that scan tool MB991958 communicates 
normally.

DTC12: Encrypted Codes are Not the Same or Not Registered.

.

DTC SET CONDITION
The encrypted code sent by the transponder is not 
the same encrypted code which is registered in the 
immobilizer-ECU.
NOTE: DTC 12 is always output together with MFI 
system DTC P0513.

.

TROUBLESHOOTING HINTS

• The encrypted code in the ignition key has not 

been properly registered 

• Malfunction of immobilizer-ECU.

.

DIAGNOSIS
Was the encrypted code registered?

YES : Replace the immobilizer-ECU and then re-register the 

encrypted code (Refer to 

P.54A-40

).

NO :  Register the encrypted code (Refer to 

P.54A-40

).

AC305231CQ

CONNECTOR: C-124

HARNESS SIDE

AC305235AF

CONNECTOR: C-310

HARNESS SIDE

IGNITION SWITCH

TSB Revision

CHASSIS ELECTRICAL

54A-18

SYMPTOM CHART

M1543007201105

CAUTION

During diagnosis, a DTC code associated with 
other system may be set when the ignition switch 
is turned on with connector(s) disconnected. On 
completion, confirm all systems for DTC code(s). 
If DTC code(s) are set, erase them all.

SYMPTOM

INSPECTION 
PROCEDURE NO.

REFERENCE PAGE

Communication with scan tool MB991958 is impossible.

1

P.54A-19

The ignition key cannot be registered.

2

P.54A-28

Engine cranks, but does not start.

3

P.54A-29

The immobilizer indicator light does not illuminate.

4

P.54A-32