Mitsubishi Galant. Manual — part 687

SWS DIAGNOSIS

TSB Revision

SIMPLIFIED WIRING SYSTEM (SWS)

54B-143

Inspection Procedure J-1: Flasher timer: Turn-signal lights does not flash when the turn-signal light
switch is turned on.

AC004213

Turn-signal Light Drive Circuit

SWS DIAGNOSIS

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SIMPLIFIED WIRING SYSTEM (SWS)

54B-144

CIRCUIT OPERATION
If the ETACS-ECU receives a signal from the turn-
signal light switch, the flasher timer circuit (which is
incorporated in the ETACS-ECU) makes the turn-
signal lights flash.

TECHNICAL DESCRIPTION (COMMENT)
The ETACS-ECU makes the turn-signal lights flash,
based on the input signals from the following
switches:

•

Ignition switch (IG1)

•

Turn-signal light switch

If the turn-signal lights do not flash normally, a defect
on the relevant circuits or the ETACS-ECU may be
suspected.

If the hazard warning lights also do not flash, a defect
in the ETACS-ECU power supply line specific to the
turn-signal lights is suspected.

NOTE: If only one of the turn-signal lights does not
flash, the light bulb may be burned out or the harness
wires between the ETACS-ECU and the light may be
defective. In this case, check the circuit by referring
to GROUP 90, Turn-signal Light and Hazard Warning
Light

P.90-80

.

TROUBLESHOOTING HINTS

•

Malfunction of the column switch (turn-signal light
and lighting switch)

•

Malfunction of the ETACS-ECU

•

Damaged harness wires or connectors

DIAGNOSIS

Required Special Tools:

•

MB991223: Test Harness Set

•

MB991502: Scan Tool (MUT-II)

•

MB991529: Diagnostic Trouble Code Check Harness

STEP 1. Check the hazard warning light operation.

Q: Do the hazard warning lights work normally?

YES : Go to Step 8 <when using scan tool MB991502> or 9

<when using a voltmeter>.

NO : Go to Step 2.

AC003079 AB

CONNECTOR
BLOCK (LH)

CONNECTOR: C-66

AC003082 AG

CONNECTORS: C-77, C-78

JUNCTION BLOCK
(FRONT VIEW)

C-77

C-78

AC003080AC

C-86

JUNCTION BLOCK
(REAR VIEW)

CONNECTORS: C-84, C-86

C-84

SWS DIAGNOSIS

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SIMPLIFIED WIRING SYSTEM (SWS)

54B-145

STEP 2. Check turn-signal light state operation.

Q: Does any turn-signal lights flash?

YES (only one side illuminates) : Go to Step 3.
NO (no lights flash at all) : Go to Step 5.

STEP 3. Check ETACS-ECU connector C-86 and junction
block connectors C-77, C-78 and C-84 for damage.
Q: Are ETACS-ECU connector C-86 and junction block

connectors C-77, C-78 and C-84 in good condition?
YES : Go to Step 4.
NO : Repair or replace them. Refer to GROUP 00E,

Harness Connector Inspection

P.00E-2

. The turn-

signal lights should flash normally.

AC003082 AG

CONNECTORS: C-77, C-78

JUNCTION BLOCK
(FRONT VIEW)

C-77

C-78

AC003080AC

C-86

JUNCTION BLOCK
(REAR VIEW)

CONNECTORS: C-84, C-86

C-84

SWS DIAGNOSIS

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SIMPLIFIED WIRING SYSTEM (SWS)

54B-146

STEP 4. Check the harness wires between ETACS-ECU
connector C-86 and junction block connectors C-77, C-78
and C-84.
Q: Are the harness wires between ETACS-ECU connector

C-86 and junction block connectors C-77, C-78 and C-84
in good condition?
YES : Replace the ETACS-ECU. The turn-signal lights

should flash normally.

NO : Repair them. The turn-signal lights should flash

normally.

STEP 5. Check the ETACS-ECU power supply circuit (for
turn-signal light) at the ETACS-ECU connector C-86.
(1)Disconnect the ETACS-ECU connector C-86 and measure

at the junction block side.

(2)Measure the voltage between terminal 18 and ground.

Q: Is the voltage approximately 12 volts (battery positive

voltage)?
YES : Replace the ETACS-ECU. The turn-signal lights

should flash normally.

NO : Go to Step 6.

STEP 6. Check ETACS-ECU connector C-86 for damage.
Q: Is ETACS-ECU connector C-86 in good condition?

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

Connector Inspection

P.00E-2

. The turn-signal lights

should flash normally.

AC003082 AG

CONNECTORS: C-77, C-78

JUNCTION BLOCK
(FRONT VIEW)

C-77

C-78

AC003080AC

C-86

JUNCTION BLOCK
(REAR VIEW)

CONNECTORS: C-84, C-86

C-84

19

20

18 17 16 15 14 13 12 11 10 9

8

7

6

5

4

3

2

1

AC002141

CONNECTOR C-86
(JUNCTION BLOCK SIDE)

AC

AC003080 AD

JUNCTION BLOCK
(REAR VIEW)

CONNECTOR: C-86