Mitsubishi Lancer (4A9 engine). Manual — part 236

SECURITY ALARM

CHASSIS ELECTRICAL

54A-606

TECHNICAL DESCRIPTION (COMMENT)
If the activated security alarm siren sounds even
though no faulty operation is made, the security
alarm siren may not be able to receive the signal
from the ETACS-ECU via the LIN cutoff control unit.
NOTE: The security alarm siren may be sounding by
false alarm. Investigate what kind of situation the
security alarm siren sounded under. Check if there
was any condition that caused false alarm.

TROUBLESHOOTING HINTS

• security alarm siren may be defective

• LIN cutoff control unit may be defective

• The ETACS-ECU may be defective

• The wiring harness or connectors may have

loose, corroded, or damaged terminals, or termi-
nals pushed back in the connector

DIAGNOSIS PROCEDURE

STEP 1. Vehicle status check when security
alarm siren is sounding
(1) Since it is suspected that the security alarm has

sounded accidentally, investigate whether the
vehicle is under the situation below. Repair if an
abnormality is found.

• The windows and sunroof are open.

• Some moving accessories are fitted in the

vehicle.

• The interior equipment has been modified

before a malfunction occurs.

(2) Set the sensitivity level of security alarm sensor

to Level 4 by using the customisation function.

(3) Check if the security alarm siren sounds during

the status of "Ready to be triggered" even though
no faulty operation is made.

Q: Is the check result normal?

YES :

Go to Step 2

NO :

The diagnosis is complete.

STEP 2. M.U.T.-III diagnosis code.
Check if diagnosis code is set to the ETACS-ECU.

Q: Is the diagnosis code set?

YES :

Diagnose the ETACS-ECU. Refer to

GROUP 54A, Diagnosis .

NO :

Go to Step 3.

STEP 3. LIN cutoff control unit check
Check the continuity of the LIN cutoff control unit.
(Refer to .)

Q: Is the check result normal?

YES :

Go to Step 4.

NO :

Replace LIN cutoff control unit.

STEP 4. Connector check: C-301 ETACS-ECU
connector, C-312 ETACS-ECU connector, C-63
LIN cutoff control unit connector

Q: Is the check result normal?

YES :

Go to Step 5.

NO :

Repair the defective connector.

STEP 5. Wiring harness check between the C-301
ETACS-ECU connector terminal No. 13 and C-63
LIN cutoff control unit connector terminal No. 3
Check the signal line for open circuit and short cir-
cuit.

Q: Is the check result normal?

YES :

Go to Step 6.

NO :

Repair the wiring harness.

STEP 6. Wiring harness check between the C-312
ETACS-ECU connector terminal No. 9 and C-63
LIN cutoff control unit connector terminal No. 8
Check the signal line for short circuit.
NOTE: Prior to the wiring harness inspection, check
C-127 intermediate connector, and repair if neces-
sary.

Q: Is the check result normal?

YES :

Go to Step 7.

NO :

Repair the wiring harness.

STEP 7. Retest the security alarm system.
Check if the activated security alarm siren sounds
even though no faulty operation is made.

Q: Is the check result normal?

YES :

The trouble can be an intermittent

malfunction (Refer to GROUP 00

− How to

Cope with Intermittent Malfunction ).

NO :

Replace the ETACS-ECU.

SECURITY ALARM

CHASSIS ELECTRICAL

54A-607

Inspection Procedure 6: Security alarm siren does not sound.

CAUTION

Before replacing the ECU, ensure that the power supply circuit, the earth circuit and the communica-
tion circuit are normal.
TECHNICAL DESCRIPTION (COMMENT)
When only the hazard warning lamp flashes and the
security alarm siren does not sound during "Exterior
protection" status, the security alarm siren may have
an internal error or the LIN cutoff control unit may be
defective.

TROUBLESHOOTING HINTS

• Security alarm siren may be defective

• LIN cutoff control unit may be defective

DIAGNOSIS PROCEDURE

STEP 1. Security alarm siren operation check
(1) Set the security alarm to the "Ready to be

triggered" condition.

(2) Open the driver's door by using the ignition key.
(3) Check that the security alarm siren sounds.

Q: Is the check result normal?

YES :

The trouble can be an intermittent

malfunction (Refer to GROUP 00

− How to

Cope with Intermittent Malfunction ).

NO :

Go to Step 2.

STEP 2. M.U.T.-III diagnosis code.
Check if diagnosis code is set to the ETACS-ECU.

Q: Is the diagnosis code set?

YES :

Diagnose the ETACS-ECU (Refer to ).

NO :

Go to Step 3.

STEP 3. LIN cutoff control unit check
Check the continuity of the LIN cutoff control unit.
(Refer to .)

Q: Is the check result normal?

YES :

Go to Step 4.

NO :

Replace LIN cutoff control unit.

STEP 4. Security alarm siren operation check
(1) Set the security alarm to the "Ready to be

triggered" condition.

(2) Open the driver's door by using the ignition key.
(3) Check that the security alarm siren sounds.

Q: Is the check result normal?

YES :

The trouble can be an intermittent

malfunction (Refer to GROUP 00

− How to

Cope with Intermittent Malfunction ).

NO :

Replace the security alarm siren.

ON-VEHICLE SERVICE

CUSTOMISATION FUNCTION

M1547003400742

By operating the M.U.T.-III ETACS system or MMCS
<Vehicles for Russia>, the following functions can be
customised. The programmed information is held
even when the battery is disconnected.

Adjustment item
(M.U.T.-III display)

Adjustment item

Adjusting content
(M.U.T.-III display)

Adjusting content

Sensitivity for security
sensor

Sensitivity level setting of
security alarm sensor
<Vehicles with security
alarm>

Level 1

100% sensitivity of
security alarm sensor
(initial condition)

Level 2

90% sensitivity of security
alarm sensor

Level 3

80% sensitivity of security
alarm sensor

Level 4

70% sensitivity of security
alarm sensor

Alarm

Enables/disables security
alarm <Vehicles with
security alarm>

Disable

Without function

Enable

With function (Initial
condition)

SECURITY ALARM

CHASSIS ELECTRICAL

54A-608

LIN CUTOFF CONTROL UNIT REMOVAL
AND INSTALLATION

M1547004800141

Pre-removal operation
• Removal of instrument panel side cover (Refer to GROUP

52A

− Instrument Panel Assembly )

• Removal of instrument panel lower (Refer to GROUP 52A

− Instrument Panel Lower ) <LHD>

• Removal of glove box cover (Refer to GROUP 52A −

Glove Box Assembly ) <RHD>

Post-installation operation
• Installation of instrument panel side cover (Refer to

GROUP 52A

− Instrument Panel Assembly )

• Installation of instrument panel lower (Refer to GROUP

52A

− Instrument Panel Lower ) <LHD>

• Installation of glove box cover (Refer to GROUP 52A −

Glove Box Assembly ) <RHD>

ACA01090AB

1

1

<LHD>

<RHD>

SECURITY ALARM

CHASSIS ELECTRICAL

54A-609

SECURITY ALARM SENSOR REMOVAL
AND INSTALLATION

M1547004900104

Removal

1.

LIN cutoff control unit

ACA00339

1

AB

2

4

3

Removal Steps

1.

Security alarm sensor assembly

2.

Security alarm sensor

3.

Security alarm sensor cover

4.

Sub harness

Removal Steps (Continued)