Mitsubishi Galant. Manual — part 669

SWS DIAGNOSIS

TSB Revision

SIMPLIFIED WIRING SYSTEM (SWS)

54B-71

CIRCUIT OPERATION.
The turn-signal light and the horn answerback
functions can be selected by the driver's desire (can
be deactivated). However, the interior lights
answerback function can not be deactivated. If all of
these devices do not operate through the
answerback function, the ETACS-ECU may be
defective.

TROUBLESHOOTING HINTS

•

Malfunction of the turn-signal light

•

Malfunction of the horn

•

Malfunction of the horn relay

•

Malfunction of the dome light

•

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

AC002299 AC

FUSIBLE LINK (1)

AC003128 AD

CONNECTOR: A-15X

HORN
RELAY

BATTERY

AC003129 AB

CONNECTOR: A-29

AC003079 AB

CONNECTOR
BLOCK (LH)

CONNECTOR: C-66

AC003082AH

JUNCTION BLOCK
(FRONT VIEW)

CONNECTORS: C-77, C-81

C-81

C-77

AC003080AF

JUNCTION BLOCK
(REART VIEW)

CONNECTOR: C-85

SWS DIAGNOSIS

TSB Revision

SIMPLIFIED WIRING SYSTEM (SWS)

54B-72

STEP 1. Check the answerback set condition.
Activate the answerback functions. (Refer to GROUP 42,
Keyless Entry System

−

On-vehicle Service

−

Enabling/

disabling the Answerback Function

P.42-68

.)

Q: Does the answerback function work normally?

YES : There is no action to be taken.
NO : Go to Step 2.

STEP 2. Check trouble symptom.

Q: Which component(s) does not operate through the

answerback?
Only the dome light : Go to Step 3.
Only the hazard warning lights : Go to Step 4.
Only the horn <Vehicles with theft-alarm system> : Go

to Step 5.

Only the horn <Vehicles without theft-alarm system> :

Go to Step 6.

None of the dome light, the turn-signal lights, and the
horn : Replace the ETACS-ECU. The answerback function

should work normally.

STEP 3. Check the dome light dimming function.

Q: Does the dome light dimming function work normally?

YES : Replace the ETACS-ECU. The answerback function

should work normally.

NO : Solve the problem first. Refer to Inspection Procedure

L-1 (

P.54B-158

).

STEP 4. Check the hazard warning light operation.

Q: Do the hazard warning lights operate normally?

YES : Replace the ETACS-ECU. The answerback function

should work normally.

NO : Solve the problem first. Refer to Inspection Procedure

J-2 (

P.54B-149

).

STEP 5. Check the theft-alarm horn operation.

Q: Does the horn work normally by the theft-alarm system?

YES : Replace the ETACS-ECU. The answerback function

should work normally.

NO : Solve the problem first. Refer to Inspection Procedure

M-2 (

P.54B-173

).

SWS DIAGNOSIS

TSB Revision

SIMPLIFIED WIRING SYSTEM (SWS)

54B-73

STEP 6. Check the horn.
The horn should sound when the battery is connected as
shown in the illustration.

Q: Does the horn sound?

YES : Go to Step 7.
NO : Replace the horn. The answerback function should

work normally.

STEP 7. Check the horn relay.

Q: Is the theft-alarm horn relay in good condition?

YES : Go to Step 8.
NO : Replace it. The answerback function should work

normally.

STEP 8. Check the horn relay power supply circuit at the
theft-alarm horn relay connector A-15X.
(1)Disconnect the horn relay connector A-15X and measure at

the relay box side.

(2)Measure the voltages between terminals 3, 4 and ground.

Q: Are the voltages approximately 12 volts (battery

positive voltage)?
YES : Go to Step 11.
NO : Go to Step 9.

AC003401

BATTERY
VOLTAGE

TESTER
CONNECTION

SPECIFIED
CONDITION

Not applied

1

−

3

Continuity

1

−

Battery (+)

terminal,
3

−

Battery (

−

)

terminal

4

−

5

Continuity

1

2 3

4

5

1

3

4

5

ACX01544

1

2

3

4

5

ACX01590AF

CONNECTOR A-15X
(RELAY BOX SIDE)

SWS DIAGNOSIS

TSB Revision

SIMPLIFIED WIRING SYSTEM (SWS)

54B-74

STEP 9. Check the horn relay connector A-15X for damage.
Q: Is horn relay connector A-15X in good condition?

YES : Go to Step 10.
NO : Repair or replace it. Refer to GROUP 00E, Harness

Connector Inspection

P.00E-2

. The answerback

function should work normally.

AC003128 AD

CONNECTOR: A-15X

HORN
RELAY

BATTERY