Mitsubishi Galant. Manual — part 686

SWS DIAGNOSIS

TSB Revision

SIMPLIFIED WIRING SYSTEM (SWS)

54B-139

NOTE: After checking junction block connectors C-78 and C-85
and intermediate connector C-66, check the wires. If junction
block connectors C-78 and C-85 and intermediate connector C-
66 are damaged, repair or replace them. Refer to GROUP 00E,
Harness Connector Inspection

P.00E-2

.

Q: Are the harness wires between combination meter

connector C-29 and fusible link (1) in good condition?
YES : There is no action to be taken.
NO : Repair or replace them. The high-beam indicator light

should work normally.

STEP 8. Check combination meter connector C-29 and
ETACS-ECU connector C-82 for damage.
Q: Are combination meter connector C-29 and ETACS-ECU

connector C-82 in good condition?
YES : Go to Step 9.
NO : Repair or replace them. Refer to GROUP 00E,

Harness Connector Inspection

P.00E-2

. The high-

beam indicator light should work normally.

AC003079 AB

CONNECTOR
BLOCK (LH)

CONNECTOR: C-66

AC003089 AD

CONNECTOR: C-29

AC003082AC

JUNCTION BLOCK
(FRONT VIEW)

CONNECTOR: C-82

SWS DIAGNOSIS

TSB Revision

SIMPLIFIED WIRING SYSTEM (SWS)

54B-140

STEP 9. Check the harness wire between combination
meter connector C-29 and ETACS-ECU connector C-82.
Q: Is the harness wire between combination meter

connector C-29 and ETACS-ECU connector C-82 in
good condition?
YES : There is no action to be taken.
NO : Repair it. The high-beam indicator light should work

normally.

STEP 10. Replacement of ECU.
(1)Replace the ETACS-ECU.
(2)The high-beam indicator light should work normally.

Q: Is the high-beam indicator light working normally?

YES : There is no action to be taken.
NO : Replace the front-ECU. The high-beam indicator light

should work normally.

Inspection Procedure I-6: Headlight, taillight: Headlight automatic shutdown function does not work
normally.

TECHNICAL DESCRIPTION (COMMENT).
The ETACS-ECU operates the headlight automatic
shutdown function, based on the signals from the
following switches:

•

Ignition switch (IG1)

•

Driver's door switch

•

Taillight switch

•

Headlight switch

If the function does work normally, a defect on
relevant input circuits, the ETACS-ECU or the front-
ECU is suspected.

TROUBLESHOOTING HINTS

•

Malfunction of the driver's door switch)

•

Malfunction of the taillight switch

•

Malfunction of the headlight switch

•

Malfunction of the ETACS-ECU

•

Malfunction of the front-ECU

•

Damaged harness wires or connectors

DIAGNOSIS

Required Special Tools:

•

MB991502: Scan Tool (MUT-II)

AC003089 AD

CONNECTOR: C-29

AC003082AC

JUNCTION BLOCK
(FRONT VIEW)

CONNECTOR: C-82

SWS DIAGNOSIS

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SIMPLIFIED WIRING SYSTEM (SWS)

54B-141

•

MB991529: Diagnostic Trouble Code Check Harness

STEP 1. Check the DTC.

Q: Does the DTC set when the ignition switch is turned to

the "LOCK" (OFF) position?
YES : Carry out the troubleshooting by referring to

Diagnostic Trouble Code Chart. Refer to

P.54B-8

.

NO : Go to Step 2 <when using scan tool MB991502> or 3

<when using a voltmeter>.

STEP 2. Check the input signal (by using scan tool
MB991502).
Check the input signals from the following switches.

•

Ignition switch (IG1)

•

Driver's door switch

•

Taillight switch

•

Headlight switch

CAUTION

To prevent damage to scan tool MB991502, always turn the
ignition switch to the "LOCK" (OFF) position before
connecting or disconnecting scan tool MB991502.
(1)Connect scan tool MB991502 to the data link connector.
(2)Check that the tone alarm of scan tool MB991502 sounds

when the input signal enters.

Q: Does the tone alarm of scan tool MB991502 sound when

the input signal enters?
YES : Go to Step 4.
NO : Check the relevant input signal circuit. Refer to

P.54B-9

.

STEP 3. Check the input signal (by using a voltmeter).
Check the input signals from the following switches.

•

Ignition switch (IG1)

•

Driver's door switch

•

Taillight switch

•

Headlight switch

(1)Use special tool MB991529 to connect a voltmeter between

ground terminal 4 or 5 and ETACS-ECU terminal 9 of the
data link connector.

(2)Check that the voltmeter indicator deflects once when the

input signal enters.

Q: Does the voltmeter indicator deflect?

YES : Go to Step 4.
NO : Check the relevant input signal circuit. Refer to

P.54B-9

.

AC003081 AB

16 PIN

MB991502

AC003083

16 PIN

AB

ETACS-ECU
TERMINAL

GROUNDED TERMINAL

MB991529

SWS DIAGNOSIS

TSB Revision

SIMPLIFIED WIRING SYSTEM (SWS)

54B-142

STEP 4. Replacement of ECU.
(1)Replace the front-ECU.
(2)The headlight automatic shutdown function should work

normally.

Q: Is the headlight automatic shutdown function working

normally?
YES : There is no action to be taken.
NO : Replace the ETACS-ECU. The headlight automatic

shutdown function should work normally.

Inspection Procedure I-7: Headlight, taillight: Headlight dimmer switch automatic resetting function
does not work normally.

TECHNICAL DESCRIPTION (COMMENT).
The headlight dimmer switch automatic resetting
function is controlled by the front-ECU. If a defect
appears, the front-ECU may be defective.

TROUBLESHOOTING HINT
Malfunction of the front-ECU

DIAGNOSIS
Replace the front-ECU.
The headlight dimmer switch automatic resetting function
should work normally.