Mitsubishi Galant. Manual — part 659

SWS DIAGNOSIS

TSB Revision

SIMPLIFIED WIRING SYSTEM (SWS)

54B-31

SCAN TOOL MB991502 COMMUNICATION IS
NOT POSSIBLE
The ETACS-ECU receives a diagnostic trouble code
and switch signals from the data link connector.

TECHNICAL DESCRIPTION (COMMENT)
The harness wires between the ETACS-ECU power
supply line or the ETACS-ECU and the data link
connector may be defective.

TROUBLESHOOTING HINTS

•

Malfunction of the ETACS-ECU

•

Damaged harness wires or connectors

DIAGNOSIS

Required Special Tools:

•

MB991223: Test Harness Set

•

MB991502: Scan Tool (MUT-II)

STEP 1. Check the communication with other systems.

Q: Can the scan tool communicate with no systems?

YES : Refer to GROUP 13A, Diagnosis

P.13A-20

or

GROUP 13B, Diagnosis.

NO (can not communicate with SWS only : Go to Step 2.

STEP 2. Check the ignition switch positions.

Q: Can scan tool MB991502 communicate with the ETACS-

ECU with the ignition switch at any position other than
"ON?"
YES : Go to Step 3.
NO : Check the ETACS-ECU battery circuits. Refer to

Inspection Procedure O-1 (

P.54B-266

).

AC003089 AB

CONNECTOR: C-23

AC003079 AB

CONNECTOR
BLOCK (LH)

CONNECTOR: C-66

AC003082AE

C-82

JUNCTION BLOCK
(FRONT VIEW)

CONNECTORS: C-73, C-82

C-73

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-32

STEP 3. Check data link connector C-23 and ETACS-ECU
connector C-82 for damage.
Q: Are data link connector C-23 and ETACS-ECU connector

C-82 in good condition?
YES : Go to Step 4.
NO : Repair or replace them. Refer to GROUP 00E,

Harness Connector Inspection

P.00E-2

. Scan tool

MB991502 should communicate with the SWS.

STEP 4. Check the harness wires between data link
connector C-23 and ETACS-ECU connector C-82.
Q: Are the harness wires between data link connector C-23

and ETACS-ECU connector C-82 in good condition?
YES : Go to Step 5.
NO : Repair them. Scan tool MB991502 should

communicate with the SWS.

STEP 5. Check the ETACS-ECU ground circuit 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 resistance between terminal 1 and ground.

Q: Is the resistance less than 2 ohm?

YES : Replace the ETACS-ECU. Scan tool MB991502

should communicate with the SWS.

NO : Go to Step 6.

AC003089 AB

CONNECTOR: C-23

AC003082AC

JUNCTION BLOCK
(FRONT VIEW)

CONNECTOR: C-82

AC003089 AB

CONNECTOR: C-23

19

20

18 17 16 15 14 13 12 11 10 9

8

7

6

5

4

3

2

1

AC002064

CONNECTOR C-86
(JUNCTION BLOCK SIDE)

AC

SWS DIAGNOSIS

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SIMPLIFIED WIRING SYSTEM (SWS)

54B-33

STEP 6. Check the 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

. Scan tool MB991502

should communicate with the SWS.

STEP 7. Check the harness wires between ETACS-ECU
connector C-86 and ground.
NOTE: After checking junction block connector C-73, check the
wires. If junction block connector C-73 is damaged, repair or
replace it. Refer to GROUP 00E, Harness Connector
Inspection

P.00E-2

.

Q: Are the harness wires between ETACS-ECU connector

C-86 and ground in good condition?
YES : There is no action to be taken.
NO : Repair them. Scan tool MB991502 should

communicate with the SWS.

Inspection Procedure B-1: Tone alarm: Ignition key reminder tone alarm function does not work
normally.

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

•

Ignition switch (IG1)

•

Key reminder switch

•

Driver's door 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 key reminder switch

•

Malfunction of the driver's door switch

•

Malfunction of the ETACS-ECU

•

Damaged harness wires or connectors

AC003080 AD

JUNCTION BLOCK
(REAR VIEW)

CONNECTOR: C-86

AC003080 AD

JUNCTION BLOCK
(REAR VIEW)

CONNECTOR: C-86

AC003082AD

JUNCTION BLOCK
(FRONT VIEW)

CONNECTOR: C-73

SWS DIAGNOSIS

TSB Revision

SIMPLIFIED WIRING SYSTEM (SWS)

54B-34

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?

•

Light reminder tone alarm function

•

Central door locking system

•

Hazard warning light

•

Interior light dimming function

•

Theft-alarm system

Q: Does any function 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)

•

Key reminder switch

•

Driver's door 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 ignition key reminder

tone alarm function should work normally.

NO : Check the relevant input circuit. Refer to

P.54B-9

.

AC003081 AB

16 PIN

MB991502