Mitsubishi Galant. Manual — part 660

SWS DIAGNOSIS

TSB Revision

SIMPLIFIED WIRING SYSTEM (SWS)

54B-35

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

•

Ignition switch (IG1)

•

Key reminder switch

•

Driver's door 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 ignition key reminder

tone alarm function should work normally.

NO : Check the relevant input circuit. Refer to

P.54B-9

.

Inspection Procedure B-2: Tone alarm: Light reminder tone alarm function does not work normally.

TECHNICAL DESCRIPTION (COMMENT)
The ETACS-ECU operates the light reminder tone
alarm function, based on input signals from the
following switches and the front-ECU:

•

Ignition switch (IG1)

•

Driver's door switch

•

Taillight switch

•

Headlight switch

If the function does not work normally, a defect on
the relevant circuit or the ETACS-ECU may be
suspected.

TROUBLESHOOTING HINTS

•

Malfunction of the driver's door switch

•

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:

•

MB991502: Scan Tool (MUT-II)

•

MB991529: Diagnostic Trouble Code Check Harness

STEP 1. Check the ETACS-ECU power supply circuit.
If the ignition switch is at "LOCK" (OFF) position, do all of the
following functions operate?

•

Ignition key reminder tone alarm function

•

Central door locking system

•

Hazard warning light

•

Interior light dimming function

•

Theft-alarm system

Q: Do any functions described above operate?

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

<when using a voltmeter>.

NO : Check the ETACS-ECU battery circuit. Refer to

Inspection Procedure O-1 (

P.54B-266

).

AC003083

16 PIN

AB

ETACS-ECU
TERMINAL

GROUNDED TERMINAL

MB991529

SWS DIAGNOSIS

TSB Revision

SIMPLIFIED WIRING SYSTEM (SWS)

54B-36

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 : Replace the ETACS-ECU. The light reminder tone

alarm function should work normally.

NO : Check the relevant input 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 : Replace the ETACS-ECU. The light reminder tone

alarm function should work normally.

NO : Check the relevant input circuit. Refer to

P.54B-9

.

Inspection Procedure B-3: Tone alarm: Seat belt tone alarm function does not work normally.

TECHNICAL DESCRIPTION (COMMENT)
The ETACS-ECU operates the seat belt tone alarm
function, based on input signals from the following
switches and the front-ECU:

•

Ignition switch (IG1)

•

Driver's seat belt switch

If the function does not work normally, a defect on
the relevant circuit or the ETACS-ECU may be
suspected.

TROUBLESHOOTING HINTS

•

Malfunction of the seat belt switch

•

Malfunction of the ETACS-ECU

•

Damaged harness wires or connectors

AC003081 AB

16 PIN

MB991502

AC003083

16 PIN

AB

ETACS-ECU
TERMINAL

GROUNDED TERMINAL

MB991529

SWS DIAGNOSIS

TSB Revision

SIMPLIFIED WIRING SYSTEM (SWS)

54B-37

DIAGNOSIS

Required Special Tools:

•

MB991502: Scan Tool (MUT-II)

•

MB991529: Diagnostic Trouble Code Check Harness

STEP 1. Check the ETACS-ECU power supply circuit.
If the ignition switch is at "LOCK" (OFF) position, do all of the
following functions operate?

•

Ignition key reminder tone alarm function

•

Central door locking system

•

Hazard warning light

•

Interior light dimming function

•

Theft-alarm system

Q: Do any functions described above operate?

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

<when using a voltmeter>.

NO : Check the ETACS-ECU battery circuit. Refer to

Inspection Procedure O-1 (

P.54B-266

).

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

•

Ignition switch (IG1)

•

Driver's seat belt 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 : Replace the ETACS-ECU. The seat belt tone alarm

function should work normally.

NO : Check the relevant input circuit. Refer to

P.54B-9

.

AC003081 AB

16 PIN

MB991502

SWS DIAGNOSIS

TSB Revision

SIMPLIFIED WIRING SYSTEM (SWS)

54B-38

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 : Replace the ETACS-ECU. The light reminder tone

alarm function should work normally.

NO : Check the relevant input circuit. Refer to

P.54B-9

.

AC003083

16 PIN

AB

ETACS-ECU
TERMINAL

GROUNDED TERMINAL

MB991529