Mitsubishi Lancer (4A9 engine). Manual - part 106

HEADLAMP

CHASSIS ELECTRICAL

54A-86

Tool

Number

Name

Use

MB991955

a. MB991824
b. MB991827
c. MB991910
d. MB991911
e. MB991825
f. MB991826

M.U.T.-III sub-
assembly

a. Vehicle 

Communicati
on Interface 
(V.C.I.)

b. M.U.T.-III 

USB cable

c. M.U.T.-III 

main harness 
A (Vehicles 
with CAN 
communicatio
n system)

d. M.U.T.-III 

main harness 
B (Vehicles 
without CAN 
communicatio
n system)

e. M.U.T.-III 

measure 
adapter

f. M.U.T.-III 

trigger 
harness

CAUTION

For vehicles with CAN 
communication, use M.U.T.-III 
main harness A to send 
simulated vehicle speed. If you 
connect M.U.T.-III main harness B 
instead, the CAN communication 
does not function correctly.
Diagnosis code, service data and 
actuator test check.

MB991223

a. MB991219
b. MB991220
c. MB991221
d. MB991222

Harness set

a. Check 

harness

b. LED harness
c. LED harness 

adapter

d. Probe

Continuity check and voltage 
measurement at harness wire or 
connector

a. For checking connector pin 

contact pressure

b. For checking power supply 

circuit

c. For checking power supply 

circuit

d. For connecting a locally sourced 

tester

MB991910

MB991826

MB991955

MB991911

MB991824

MB991827

MB991825

a

b

c

d

e

f

DO NOT USE

MB991223

a

d

c

b

DO NOT USE

BA

HEADLAMP

CHASSIS ELECTRICAL

54A-87

SERVICE PRECAUTIONS <DISCHARGE 
HEADLAMP>

M1540100300151

Before checking the discharge headlamp related 
parts, be sure to read the following warnings and pre-
cautions carefully, and then perform necessary oper-
ations.

MB992006

Extra fine probe

Continuity check and voltage 
measurement at harness wire or 
connector

Tool

Number

Name

Use

MB992006

HEADLAMP

CHASSIS ELECTRICAL

54A-88

DANGER

•

Do not touch the socket and the connec-
tor while the headlamps are on. High volt-
age is applied to the bulb socket and 
connector during headlamp operation. 
The operator may be burnt or dead due to 
an electric shock by high voltage.

•

Do not attempt to use a tester to check 
them. If the bulb socket and connectors 
should be inspected using a tester, the 
operator may be burnt or dead due to an 
electric shock by high voltage.

•

Do not turn ON the headlamps while the 
controller or the bulb is removed. If the 
headlamps are turned ON with the con-
troller or bulb removed, the operator may 
get burned by the bulb of a high tempera-
ture. The operator may be burnt or dead 
due to an electric shock by high voltage.

•

Before service work, turn the lighting 
switch OFF and disconnect the battery 
terminal and the controller connector in a 
dry place. Do not touch the components 
with wet hands. If you work on the compo-
nents with wet hands or in wet conditions, 
the operator may be burnt or dead due to 
an electric shock by high voltage.

WARNING

Do not illuminate the bare headlamp bulb. 
(Do not illuminate the headlamp using other 
than the vehicle power supply.) If the head-
lamp bulb illuminates without fitting it in the 
headlamp unit, it may burst due to rise in its 
internal pressure.

CAUTION

When reusing the controller with the discharge 
headlamp damaged, observe the inspection pro-
cedures for the related parts of the discharge 
headlamp before determining the reusability of 
the controller. If you fail to observe "How to 
check discharge headlamp components," the 
vehicle may be damaged.

1. CHECKING PROCEDURE FOR DISCHARGE HEADLAMP RELATED PARTS 
(INSPECTION PROCEDURE WHEN REUSING THE CONTROLLER)

1 

− 1 VISUAL CHECK OF CONTROLLER (CASE)

If any of the check items below are found, replace 
the controller.

HEADLAMP

CHASSIS ELECTRICAL

54A-89

1 

− 2 CHECK OF WIRING HARNESS BETWEEN CONTROLLER AND BULB

If any of the check items below are found, replace 
the wiring harness between the controller and the 
bulb.

DANGER

If the wiring harness between the controller 
and the bulb is damaged, always replace it. 
Attempting to repair the wiring harness may 
cause a melted harness wire, or may result in 
a burn or death due to an electric shock by 
high voltage.

1 

− 3 CHECK OF CONTROLLER OPERATION

If any of the abnormalities below are found, replace 
the controller.

NOTE: Ensure that the headlamp control system and 
its circuit (power supply control at engine start and 
during steady illumination, high-voltage generating 
circuit, etc.) are working normally. Then, check 
whether any internal breakage has occurred in the 
controller. However, some internal breakage may not 
be found.

2. Troubleshooting procedure for discharge headlamp (diagnostic procedure for mal-
functions)

1. Check that the connectors are connected 

securely and the fuse has not been blown.

2. Before troubleshooting, read through the "Symp-

tom chart" to understand what and how you 
should do. Follow all the procedures carefully.

3. The components should be checked with their 

connectors disconnected.

Items to be checked

Why the controller should be replaced

Obvious deformation (warping, twisting, dents, nicks, 
chipped edges) of controller case

The printed circuit board or the element(s) may be 
cracked

Damaged connector (chipped or cracked plastics, or 
deformed terminal)

The damaged part(s) may cause poor connection or 
short circuit.

Items to be checked

Why the controller should be replaced

Wiring harness shield damaged

Abnormal noise may cause.

Damaged connector (chipped or cracked plastics, or 
deformed terminal)

The damaged part(s) may cause poor connection or 
short circuit.

Check item (Check of illumination operation)
With the headlamp bulb in the cold state (with the lamp turned off for 10 minutes or more) and in warm state 
(after the lamp is illuminated for 15 minutes or more, it is turned off for 1 minute), turn ON and OFF the 
headlamp several times, and then check that the headlamp illuminates without fail.
Observe the headlamps until they illuminate steadily (approximately 5 minutes after switching on them). 
Check that the headlamps do not flash or flicker.
Turn on the headlamps for 30 minutes. Check that the brightness is the same between right and left lamps.
Turn on the headlamps for 30 minutes. Check that the headlamps do not flash or flicker for 30 minutes.