Mitsubishi Lancer (4A9 engine). Manual — part 233

SECURITY ALARM

CHASSIS ELECTRICAL

54A-594

DIAGNOSIS PROCEDURE

STEP 1. 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 2.

STEP 2. 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 3.

STEP 3. Replace the security alarm siren
temporarily, and check whether the diagnosis
code is set.
Check again if the diagnosis code is set to the
ETACS-ECU.
(1) Erase the diagnosis code.
(2) Turn the ignition switch from the LOCK (OFF)

position to the ON position.

(3) Check if diagnosis code is set.

Q: Is the diagnosis code set?

YES :

Replace the ETACS-ECU.

NO :

Replace the security alarm siren.

Code No.B120B Security alarm sensor error

CAUTION

Before replacing the ECU or sensor, ensure that the power supply circuit, the earth circuit and the
communication circuit are normal.
DIAGNOSTIC FUNCTION
The security alarm sensor communicates with the
ETACS-ECU via the LIN bus line. If the diagnosis
code No. B120B is set, the security alarm sensor
itself may be defective.
NOTE:

.

•

Diagnosis code No.B120B may be set when the
security alarm sensor cover is improperly
installed or is removed. Check if the security
alarm sensor cover is properly installed.

•

Diagnosis code No.B120B is set when the ultra-
sonic wave transmission/reception part of the
security alarm sensor is covered. Check if the
ultrasonic wave transmission/reception part of the
security alarm sensor was covered.

TROUBLESHOOTING HINT
Malfunction of the security alarm sensor

DIAGNOSIS PROCEDURE

STEP 1. 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 2.

STEP 2. Security alarm sensor operation check
Ultrasonic wave sensor check

1. With the windows of the vehicle opened, set the

security alarm to the "Ready to be triggered" con-
dition.

2. Put the arm from the outside to the inside of the

vehicle.

3. Check that the security alarm siren sounds.

Tilt angle sensor check

1. Set the security alarm to the "Ready to be trig-

gered" condition.

2. Raise the front wheels or rear wheels.
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 3.

STEP 3. M.U.T.-III diagnosis code.
Check if diagnosis code No. B120A is set to the
ETACS-ECU.

Q: Is diagnosis code No. B120A set?

SECURITY ALARM

CHASSIS ELECTRICAL

54A-595

YES :

Perform the troubleshooting of diagnosis

code No.B120A. (Refer to )

NO <The ultrasonic wave sensor is defective, or
the ultrasonic wave sensor and the inclination
sensor are defective> :

Go to step 4.

NO <Only the inclination sensor is defective> :

Go

to step 5.

STEP 4. Check the customise function.
Check if the ultrasonic wave sensor of the security
alarm senor operates when the sensitivity of the
security alarm senor is set to "Level 1".

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 5.

STEP 5. Replace the security alarm sensor
temporarily, and check whether the diagnosis
code is set.
Check again if the diagnosis code is set to the
ETACS-ECU.
(1) Erase the diagnosis code.
(2) Turn the ignition switch from the LOCK (OFF)

position to the ON position.

(3) Check if diagnosis code is set.

Q: Is the diagnosis code set?

YES :

Replace the ETACS-ECU.

NO :

Replace the security alarm sensor.

Code No.B120C Security Alarm Siren Flat Battery

CAUTION

Before replacing the ECU or sensor, ensure that the power supply circuit, the earth circuit and the
communication circuit are normal.
DIAGNOSTIC FUNCTION
The diagnosis code No.B120C is set when the volt-
age of the rechargeable battery is low, or when the
battery inside the security alarm siren has an error.
NOTE: The rechargeable battery integrated in the
security alarm siren is charged by turning the ignition
switch to the ON position.

TROUBLESHOOTING HINT

• Abnormality in security alarm siren

• Service life of rechargeable battery

• Since the vehicle had been stationary for long

time, the rechargeable battery remained
uncharged. This reduced voltage.

DIAGNOSIS PROCEDURE

M.U.T.-III diagnosis code.
Recheck whether the diagnosis code is set.
(1) Charge the rechargeable battery of the security

alarm siren by turning the ignition switch to the

ON position. (In principle, charge the battery for
30 minutes or more.)

(2) Erase the diagnosis code.
(3) After the diagnosis code is erased, turn the

ignition switch to the LOCK (OFF) position.

(4) Activate the security alarm once, and then cancel

it.
NOTE: Note that after erasing diagnosis code
No.B120C, if the ignition switch is turned from the
LOCK (OFF) position to the ON position before
activating the security alarm, diagnosis code
No.B120C will be set even though the system is
normal.

(5) Turn the ignition switch from the LOCK (OFF)

position to the ON position.

(6) On completion, check that the diagnosis code is

not reset.

Q: Is the diagnosis code set?

YES :

Replace the security alarm siren.

NO :

The diagnosis is complete.

SECURITY ALARM

CHASSIS ELECTRICAL

54A-596

TROUBLE SYMPTOM CHART

M1547001500970

Trouble symptom

Inspection
Procedure
No.

Reference
page

The security alarm is not armed (the security indicator does not illuminate).

1

The interior alarm does not work normally while the security alarm is triggered.

2

The hazard warning lamps do not flash while the security alarm is triggered.

3

Horns do not sound while the security alarm system is triggered.

4

The activated security alarm siren sounds even though no faulty operation is
made.

5

Security alarm siren does not sound.

6

SECURITY ALARM

CHASSIS ELECTRICAL

54A-597

SYMPTOM PROCEDURES

Inspection Procedure 1: The security alarm is not armed (The security indicator does not illuminate).

CAUTION

Before replacing the ECU, ensure that the power supply circuit, the earth circuit and the communica-
tion circuit are normal.

Security Indicator Circuit

SECURITY
INDICATOR

ETACS-
ECU

CENTRE
PANEL
UNIT

Wire colour code
B : Black LG : Light green G : Green L : Blue W : White Y : Yellow SB : Sky blue
BR : Brown O : Orange GR : Grey R : Red P : Pink V : Violet PU : Purple SI : Silver

NOTE

:DIESEL
:PETROL

FUSIBLE
LINK

38

36

ENGINE
COMPARTMENT

RELAY BOX