Mitsubishi Galant. Manual — part 656

SWS DIAGNOSIS

TSB Revision

SIMPLIFIED WIRING SYSTEM (SWS)

54B-19

DTC 13: Front-ECU fault

AC004199

Front-ECU Power Supply and SWS Communication Circuit

SWS DIAGNOSIS

TSB Revision

SIMPLIFIED WIRING SYSTEM (SWS)

54B-20

CIRCUIT OPERATION

•

The front-ECU is energized by the battery and
the ignition switch (IG2). If one of the harness
wires has an open circuit, power will be supplied
by the other active harness wire.

•

The front-ECU communicates with other ECUs
and performs control functions through the SWS
communication line.

DTC SET CONDITION
This DTC is displayed when the front-ECU sends an
abnormal signal to the ETACS-ECU.

TROUBLESHOOTING HINTS

•

Malfunction of the front-ECU

•

Malfunction of the ETACS-ECU

•

Damaged harness wires or connectors

DIAGNOSIS

Required Special Tools:

•

MB991223: Harness Set

•

MB991502: Scan Tool (MUT-II)

STEP 1. Check the ignition switch position.

Q: Does DTC 13 set with the ignition switch at "ON"

position?
YES : Go to Step 5.
NO : Go to Step 2.

ACX02500 AD

BATTERY

CONNECTOR: A-09X

AC003079 AB

CONNECTOR
BLOCK (LH)

CONNECTOR: C-66

AC003082AE

C-82

JUNCTION BLOCK
(FRONT VIEW)

CONNECTORS: C-73, C-82

C-73

AC003080 AB

JUNCTION BLOCK
(REAR VIEW)

CONNECTOR: C-84

SWS DIAGNOSIS

TSB Revision

SIMPLIFIED WIRING SYSTEM (SWS)

54B-21

STEP 2. Check the front-ECU power supply circuit (battery
circuit) at the front-ECU connector A-09X.
(1)Disconnect the front-ECU connector A-09X and measure at

the relay box side.

(2)Measure the voltage between terminal 16 and ground.

Q: Is the voltage approximately 12 volts (battery positive

voltage)?
YES : Replace the front-ECU. Confirm the DTC 13 is not

displayed.

NO : Go to Step 3.

STEP 3. Check the front-ECU connector A-09X for damage.
Q: Is front-ECU connector A-09X in good condition?

YES : Go to Step 4.
NO : Repair or replace it. Refer to GROUP 00E, Harness

Connector Inspection

P.00E-2

. Confirm the DTC 13

is not displayed.

STEP 4. Check the harness wire between front-ECU
connector A-09X and battery.
Q: Is the harness wire between front-ECU connector A-09X

and battery in good condition?
YES : There is no action to be taken.
NO : Repair it. Confirm the DTC 13 is not displayed.

17 16 15 14 13

12 11 10 9 8 7 6 5 4

3 2 1

AC002062

CONNECTOR A-09X
(RELAY BOX SIDE)

AB

ACX02500 AD

BATTERY

CONNECTOR: A-09X

ACX02500 AD

BATTERY

CONNECTOR: A-09X

SWS DIAGNOSIS

TSB Revision

SIMPLIFIED WIRING SYSTEM (SWS)

54B-22

STEP 5. Check the front-ECU ground circuit at the front-
ECU connector A-09X.
(1)Disconnect the front-ECU connector A-09X and measure at

the relay box side.

(2)Measure the resistance between terminal 1 and ground.

Q: Is the resistance less than 2 ohm?

YES : Go to Step 8.
NO : Go to Step 6.

STEP 6. Check the front-ECU connector A-09X for damage.
Q: Is front-ECU connector A-09X in good condition?

YES : Go to Step 7.
NO : Repair or replace it. Refer to GROUP 00E, Harness

Connector Inspection

P.00E-2

. Confirm the DTC 13

is not displayed.

STEP 7. Check the harness wire between front-ECU
connector A-09X and ground.
Q: Is the harness wire between front-ECU connector A-09X

and ground in good condition?
YES : There is no action to be taken.
NO : Repair it. Confirm the DTC 13 is not displayed.

17 16 15 14 13

12 11 10 9 8 7 6 5 4

3 2 1

AC002063

CONNECTOR A-09X
(RELAY BOX SIDE)

AB

ACX02500 AD

BATTERY

CONNECTOR: A-09X

ACX02500 AD

BATTERY

CONNECTOR: A-09X