Mitsubishi Lancer (4A9 engine). Manual - part 123

HEADLAMP AUTOMATIC LEVELLING SYSTEM

CHASSIS ELECTRICAL

54A-154

YES : 

The trouble can be an intermittent 

malfunction (Refer to GROUP 00 

− How to 

use Troubleshooting/inspection Service 
Points 

− How to Cope with Intermittent 

Malfunction ).

NO : 

Repair the wiring harness.

STEP 4. Voltage measurement at the C-14 
headlamp automatic levelling-ECU connector
(1) Disconnect the connector, and measure at the 

wiring harness side.

(2) Turn the ignition switch to the ON position.
(3) Measure the voltage between the C-14 headlamp 

automatic levelling-ECU connector terminal No. 
12 and the body earth.

OK: System voltage

Q: Is the check result normal?

YES : 

Go to Step 7.

NO : 

Go to Step 5.

STEP 5. M.U.T.-III data list
Check the ETACS-ECU service data.

• Turn the ignition switch to the ON position.

OK: Normal conditions is displayed.

Q: Is the check result normal?

YES : 

Go to Step 6.

NO : 

Troubleshoot the ETACS-ECU. Refer to 
Inspection Procedure 2 "The ignition switch 
(IG1) signal is not received" .

STEP 6. Wiring harness check between the C-14 
headlamp automatic levelling-ECU connector 
terminal No. 12 and the fusible link (34) <except 
1800-diesel> or (44) <1800-diesel>
NOTE: Prior to the wiring harness inspection, check 
ETACS-ECU connectors C-309, C-317, joint connec-
tor C-150 and intermediate connector C-128, and 
repair if necessary.

Q: Is the check result normal?

YES : 

The trouble can be an intermittent 

malfunction (Refer to GROUP 00 

− How to 

use Troubleshooting/inspection Service 
Points 

− How to Cope with Intermittent 

Malfunction ).

NO : 

Repair the wiring harness.

STEP 7. Retest the system
Check that the headlamp automatic levelling system 
or AFS functions works normally.

Q: Is the check result normal?

YES : 

The trouble can be an intermittent 

malfunction (Refer to GROUP 00 

− How to 

use Troubleshooting/inspection Service 
Points 

− How to Cope with Intermittent 

Malfunction ).

NO : 

Replace the headlamp automatic levelling-
ECU.

Inspection Procedure 2: The both headlamp automatic levelling systems (right and left) do not work 
normally. 

CAUTION

Before replacing the ECU, ensure that the power 
supply circuit, the earth circuit and the communi-
cation circuit are normal.
COMMENTS ON TROUBLE SYMPTOM
If the both headlamp automatic levelling systems 
(right and left) do not work normally, automatic level-
ling-ECU initialization, each rear height sensor, con-
nector assembly or automatic levelling-ECU may be 
defective.

PROBABLE CAUSES

• Malfunction of headlamp automatic levelling-ECU 

initialization

• Rear height sensor improperly installed

• Malfunction of rear height sensor

• Malfunction of headlamp automatic levelling-ECU

• Connector assembly improperly installed

• Damaged connectors

Item No.

Item name

Normal 
condition

Item 254

IG voltage

System voltage

HEADLAMP AUTOMATIC LEVELLING SYSTEM

CHASSIS ELECTRICAL

54A-155

DIAGNOSIS PROCEDURE

STEP 1. Connector assembly installation status 
check

Check that the connector assembly is installed prop-
erly.

Q: Is the check result normal?

YES : 

Go to Step 2.

NO : 

Install the connector assembly properly.

STEP 2. Connector check: A-01 connector 
assembly connector, C-14 headlamp automatic 
levelling-ECU connector

Q: Is the check result normal?

YES : 

Go to Step 3.

NO : 

Repair the defective connector.

STEP 3. Rear height sensor installation status 
check
Check that the rear height sensor is installed prop-
erly.

Q: Is the check result normal?

YES : 

Go to Step 4.

NO : 

Install the rear height sensor properly.

STEP 4. Rear height sensor check
Check that the rear height sensor is normal (Refer to 
).

Q: Is the check result normal?

YES : 

Go to Step 5.

NO : 

Replace the rear height sensor.

STEP 5. Retest the system
Check that the automatic levelling operates normally.

Q: Is the check result normal?

YES : 

The trouble can be an intermittent 

malfunction (Refer to GROUP 00 

− How to 

use Troubleshooting/inspection Service 
Points 

− How to Cope with Intermittent 

Malfunction ).

NO : 

Replace the headlamp automatic levelling-
ECU.

Inspection Procedure 3: One of the automatic levellings does not work.

CAUTION

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

ACB01884

AB

A-01
Connector assembly

AB

ACA00916

A-52 (B)

Connectors: A-36, A-52

A-36 (B)

AC

ACA00892

Connector: C-14 <LHD>

AS

HEADLAMP AUTOMATIC LEVELLING SYSTEM

CHASSIS ELECTRICAL

54A-156

COMMENTS ON TROUBLE SYMPTOM
When one of the automatic levellings does not work, 
the wiring harness and connector(s) between the 
headlamp automatic levelling-ECU and the head-
lamp levelling unit, or the headlamp assembly (head-
lamp levelling unit) may have a problem.

PROBABLE CAUSES

• Malfunction of headlamp assembly (headlamp 

levelling unit)

• Malfunction of headlamp automatic levelling-ECU

• Damaged harness wires and connectors

DIAGNOSIS PROCEDURE

STEP 1. Headlamp levelling unit check
Perform a levelling motor drive test of the headlamp 
levelling unit to check that the motor is driven. Refer 
to .

Q: Is the check result normal?

YES : 

The trouble can be an intermittent 

malfunction (Refer to GROUP 00 

− How to 

Use Troubleshooting/Inspection Service 
Points 

− How to Cope with Intermittent 

Malfunctions ).

NO (The left levelling motor is not driven.) : 

Go to 

Step 2.

NO (The right levelling motor is not driven.) : 

Go to 

Step 6.

STEP 2. Connector check: C-14 Headlamp 
automatic levelling-ECU connector, A-36 
headlamp assembly (LH) connector

Q: Is the check result normal?

YES : 

Go to Step 3.

NO : 

Repair the defective connector.

STEP 3. Wiring harness check between the C-14 
headlamp automatic levelling-ECU connector 
terminal No. 7/14/26 and the A-36 headlamp 
assembly (LH) connector terminal No. 3/6/2

• Check the power supply lines, earth lines and sig-

nal lines for open circuit.

Q: Is the check result normal?

YES : 

Go to Step 4.

NO : 

Repair the wiring harness.

STEP 4. M.U.T.-III data list
(1) Disconnect the headlamp assembly (LH) and 

(RH) connector.

(2) Turn the ignition switch from "LOCK" (OFF) 

position to "ON" position.

OK: Normal condition is displayed.

Q: Is the check result normal?

YES : 

Go to Step 5.

NO : 

Replace the headlamp automatic levelling-
ECU.

STEP 5. Check the headlamp assembly (LH).
Check the headlamp assembly (LH) for internal fail-
ure.
(1) Disconnect the headlamp assembly (RH) 

connector.

(2) Turn the ignition switch from "LOCK" (OFF) 

position to "ON" position.

(3) Perform the drive test using the M.U.T.-III. Refer 

to .

Q: Is the check result normal?

YES : 

Go to Step 10.

NO : 

Replace the headlamp assembly (LH).

STEP 6. Connector check: C-14 Headlamp 
automatic levelling-ECU connector, A-52 
headlamp assembly (RH) connector

Q: Is the check result normal?

YES : 

Go to Step 7.

NO : 

Repair the defective connector.

ACA00895AR

Connector: C-14 <RHD>

Item No.

Item name

Normal 
condition

Item 68

A/L actuator 
output voltage

Indicates the 
voltage value of 
system voltage 
within the range 
of 20 to 80%.

HEADLAMP AUTOMATIC LEVELLING SYSTEM

CHASSIS ELECTRICAL

54A-157

STEP 7. Wiring harness check between the C-14 
headlamp automatic levelling-ECU connector 
terminal No. 6/13/25 and the A-52 headlamp 
assembly (RH) connector terminal No. 3/6/2

• Check the power supply lines, earth lines and sig-

nal lines for open circuit.

Q: Is the check result normal?

YES : 

Go to Step 8.

NO : 

Repair the wiring harness.

STEP 8. M.U.T.-III data list
(1) Disconnect the headlamp assembly (LH) and 

(RH) connector.

(2) Turn the ignition switch from "LOCK" (OFF) 

position to "ON" position.

OK: Normal condition is displayed.

Q: Is the check result normal?

YES : 

Go to Step 9.

NO : 

Replace the headlamp automatic levelling-
ECU.

STEP 9. Check the headlamp assembly (RH).
Check the headlamp assembly (RH) for internal fail-
ure.
(1) Disconnect the headlamp assembly (LH) 

connector.

(2) Turn the ignition switch from "LOCK" (OFF) 

position to "ON" position.

(3) Perform the drive test using the M.U.T.-III. Refer 

to .

Q: Is the check result normal?

YES : 

Go to Step 10.

NO : 

Replace the headlamp assembly (RH).

STEP 10. Retest the system
Check that the automatic levelling of the right head-
lamp operates normally.

Q: Is the check result normal?

YES : 

The trouble can be an intermittent 

malfunction (Refer to GROUP 00 

− How to 

Use Troubleshooting/Inspection Service 
Points 

− How to Cope with Intermittent 

Malfunction ).

NO : 

Replace the headlamp automatic levelling-
ECU.

DATA LIST REFERENCE TABLE

M1540305200272

Item No.

Item name

Normal 
condition

Item 68

A/L actuator 
output voltage

Indicates the 
voltage value of 
system voltage 
within the range 
of 20 to 80%.

Item No. M.U.T.-III display

Condition

Normal condition

1

AFS/ACL:AFS OFF SW

−

OFF (Not present)

2

ECU power supply voltage

Ignition switch: ON position

System voltage

3

A/L:HS power supply 
voltage

Ignition switch: ON position

4.2 

− 5.7 V

5

A/L:Rear HS signal voltage Ignition switch: ON position

0.7 

− 4.1 V

7

A/L:Rear HS initial position Ignition switch: ON position

4.2 

− 5.7 V

8

A/L:HS initialization status

The headlamp automatic levelling-ECU 
initialisation is not implemented.

Not run

The headlamp automatic levelling-ECU 
initialisation is completed.

Completed

9

AFS/ACL:Vehicle 
speed(CAN input)

Perform a test run of the vehicle.

The values displayed 
on the speedometer 
and M.U.T.-III are 
almost the same.