Mitsubishi Galant 9G. Manual - part 136

INPUT SIGNAL PROCEDURES

TSB Revision

SIMPLIFIED WIRING SYSTEM (SWS)

54B-540

INSPECTION PROCEDURE N-8: Transmitter: ETACS-ECU does not receive any signal from the lock, 
unlock, trunk or panic switch.

.

CIRCUIT OPERATION

The ETACS-ECU receives signal through its receiver 
from the transmitter, and operates the keyless entry 
system according to the signal.

.

TECHNICAL DESCRIPTION (COMMENT)

If the signal is not normal, the keyless entry transmit-
ter does not work normally.

.

TROUBLESHOOTING HINTS

• The transmitter may be defective

• The ETACS-ECU may be defective

AC002099AB

Receiver and Transmitter Communication Circuit

INPUT SIGNAL PROCEDURES

TSB Revision

SIMPLIFIED WIRING SYSTEM (SWS)

54B-541

DIAGNOSIS

Required Special Tool:

• MB991223: Harness Set

STEP 1. Register the transmitter.
Register the transmitter. Refer to GROUP 42, Keyless Entry 
System, On-vehicle Service, How to register secret code 

P.42-71

.

Q: Can the transmitter be registered correctly?

YES : If the transmitter works normally, the input signal from 

the transmitter should be normal.

NO :  Go to Step 2.

STEP 2. Check the transmitter battery.
Measure the voltage of the transmitter battery.

• The value should be approximately 2.5 - 3.2 volts.

Q: Is the measured voltage approximately 2.5 - 3.2 volts 

(battery positive voltage)?
YES : Go to Step 3.
NO :  Replace the battery. If the transmitter can be 

registered normally, and operates normally, it 
indicates that the transmitter is sending normal signal 
to the ECU.

STEP 3. Check the transmitter.
Replace the transmitter and register the code. Refer to GROUP 
42, Keyless Entry System, On-vehicle Service, How to register 
secret code 

P.42-71

.

Q: Can the transmitter be registered correctly?

YES : If the transmitter works normally, the input signal from 

the transmitter should be normal.

NO :  Replace the ETACS-ECU. If the transmitter works 

normally, the input signal from the transmitter should 
be normal.

ACX01609

INPUT SIGNAL PROCEDURES

TSB Revision

SIMPLIFIED WIRING SYSTEM (SWS)

54B-542

INSPECTION PROCEDURE N-9: ETACS-ECU does not receive any interior light loaded signal.

IGNITION 
SWITCH (ACC)

IGNITION 
SWITCH (IG1)

BATTERY

RELAY 
BOX

JOINT 
CONNECTOR (1)

JUNCTION BLOCK

ETACS-ECU

LOAD 
DETERMINATION 
CIRCUIT

POWER 
SOURCE

INTERIOR LIGHT CUT BACK-UP 
CIRCUIT

KEEP RELAY

·MAP LIGHT ASSEMBLY
 <WITHOUT SUNROOF>
·OVER HEAD CONSOLE
 <WITH SUNROOF>
·REAR DOME LIGHT

JUNCTION BLOCK SIDE

Interior Light Automatic Shut-Down Function Circuit

INPUT SIGNAL PROCEDURES

TSB Revision

SIMPLIFIED WIRING SYSTEM (SWS)

54B-543

.

CIRCUIT OPERATION

The ETACS-ECU operates the following equipment 
or functions by the interior light loaded signal:

• Interior light automatic shut-down function

• Dome light

• Ignition key hole illumination light

.

TECHNICAL DESCRIPTION (COMMENT)

If the signal is not normal, the equipment or functions 
described in "CIRCUIT OPERATION" do not work 
normally.

.

TROUBLESHOOTING HINTS

• The wiring harness or connectors may have 

loose, corroded, or damaged terminals, or termi-
nals pushed back in the connector

• The ETACS-ECU may be defective

DIAGNOSIS

Required Special Tool:

• MB991223: Harness Set

STEP 1. Check ETACS-ECU connector C-219 for loose, 
corroded or damaged terminals, or terminals pushed back 
in the connector.
Q: Is ETACS-ECU connector C-219 in good condition?

YES : Go to Step 2.
NO :  Repair or replace the damaged component(s). Refer 

to GROUP 00E, Harness Connector Inspection 

P.00E-2

. If the functions or equipment described in 

"CIRCUIT OPERATION" work normally, the interior 
light loaded signal should be normal.

AC305231

CONNECTOR: C-01

AY

AC305415AS

CONNECTORS: C-214, C-215

C-214

C-215

AC305413AB

CONNECTOR: C-219

JUNCTION BLOCK

(REAR VIEW)

AC305413 AG

CONNECTOR: C-219

JUNCTION BLOCK SIDE

JUNCTION BLOCK

(REAR VIEW)