Mitsubishi Galant. Manual — part 688

SWS DIAGNOSIS

TSB Revision

SIMPLIFIED WIRING SYSTEM (SWS)

54B-147

STEP 7. Check the harness wires between ETACS-ECU
connector C-86 and battery.

NOTE: After checking junction block connector C-78 and
intermediate connector C-66, check the wires. If junction block
connector C-78 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 ETACS-ECU connector

C-86 and battery in good condition?
YES : There is no action to be taken.
NO : Repair them. The turn-signal lights should flash

normally.

AC003080 AD

JUNCTION BLOCK
(REAR VIEW)

CONNECTOR: C-86

AC003079 AB

CONNECTOR
BLOCK (LH)

CONNECTOR: C-66

AC003082 AF

JUNCTION BLOCK
(FRONT VIEW)

CONNECTOR: C-78

SWS DIAGNOSIS

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SIMPLIFIED WIRING SYSTEM (SWS)

54B-148

STEP 8. Check the input signal (by using scan tool
MB991502).
Check the input signals from the following switches.

•

Ignition switch (IG1)

•

Turn-signal light 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 : Replace the ETACS-ECU. The turn-signal lights

should flash normally.

NO : Check the relevant input signal circuit. Refer to

P.54B-9

.

STEP 9. Check the input signal (by using a voltmeter).
Check the input signals from the following switches.

•

Ignition switch (IG1)

•

Turn-signal light 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 : Replace the ETACS-ECU. The turn-signal lights

should flash normally.

NO : Check the relevant input signal circuit. Refer to

P.54B-9

.

Inspection Procedure J-2: Flasher timer: Hazard warning lights does not flash when the hazard
warning light switch is turned on.

Turn-signal LIght Drive Circuit

•

Refer to Inspection Procedure J-1 (

P.54B-144

).

CIRCUIT OPERATION
If the ETACS-ECU receives a signal from the hazard
warning 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 hazard warning
light switch. If the turn-signal lights do not flash
normally, the hazard warning light switch input circuit
or the ETACS-ECU may be defective.
If the turn-signal lights do not flash, a defect in the
ETACS-ECU power supply line specific to the turn-
signal lights is suspected.

AC003081 AB

16 PIN

MB991502

AC003083

16 PIN

AB

ETACS-ECU
TERMINAL

GROUNDED TERMINAL

MB991529

SWS DIAGNOSIS

TSB Revision

SIMPLIFIED WIRING SYSTEM (SWS)

54B-149

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 hazard warning light switch

•

Malfunction of the ETACS-ECU

•

Damaged harness wires or connectors

DIAGNOSIS

Required Special Tools:

•

MB991502: Scan Tool (MUT-II)

•

MB991529: Diagnostic Trouble Code Check Harness

STEP 1. Check the turn-signal light operation.

Q: Do the turn-signal lights work normally?

YES : Go to Step 2 <when using scan tool MB991502> or 3

<when using a voltmeter>.

NO : Solve the problem first. Refer to Inspection Procedure

J-1 (

P.54B-144

).

STEP 2. Check the input signal (by using scan tool
MB991502).
Check the input signals from the hazard warning light 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 : Replace the ETACS-ECU. The hazard warning lights

should flash normally.

NO : Check the hazard warning light switch input circuit.

Refer to Inspection Procedure N-4 (

P.54B-190

).

STEP 3. Check the input signal (by using a voltmeter).
Check the input signals from the hazard warning light 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 : Replace the ETACS-ECU. The hazard warning lights

should flash normally.

NO : Check the hazard warning light switch input circuit.

Refer to Inspection Procedure N-4 (

P.54B-190

).

AC003081 AB

16 PIN

MB991502

AC003083

16 PIN

AB

ETACS-ECU
TERMINAL

GROUNDED TERMINAL

MB991529

SWS DIAGNOSIS

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SIMPLIFIED WIRING SYSTEM (SWS)

54B-150

Inspection Procedure K-1: Fog light: Fog lights do not illuminate when the fog light switch is turned
on.

Fog Light Relay Drive Circuit

AC004214