Mitsubishi Lancer Evolution IX. Manual - part 104

HOW TO USE TROUBLESHOOTING/INSPECTION SERVICE POINTS

GENERAL

00-9

HOW TO USE THE INSPECTION PROCE-
DURES

The causes of many of the problems occurring in 
electric circuitry are generally the connectors, com-
ponents, the ECU, the wiring harnesses between 
connectors, in that order. These inspection proce-
dures follow this order. They first try to discover a 
problem with a connector or a defective component.

AC301964 AB

 Relevant circuit(s) of the component which
 the Code No. indicates are described.

AC305342AD

Explains about the basic 
operation of the components.

Explains about 
technical details.

Describes the 
conditions for that 
diagnosis code being
set.

Start of diagnosis
procedure

Describes possible
causes(s) for that 
diagnosis code.

Describes 
inspection
procedure.

M.U.T.-ll/lll data list

PROCEDURE

HOW TO USE TROUBLESHOOTING/INSPECTION SERVICE POINTS

GENERAL

00-10

HARNESS CHECK

Check for an open or short circuit in the harness 
between the terminals which were faulty according to 
the connector measurements. Carry out this inspec-
tion while referring to the Electrical Wiring Manual. 
Here, "Check the wiring harness between the power 
supply and terminal xx" also includes checking for 
blown fuse. For inspection service points when there 
is a blown fuse, refer to "Inspection Service Points 
for a Blown Fuse."

MEASURES TO TAKE AFTER 
REPLACING THE ECU

If the trouble symptoms have not disappeared even 
after replacing the ECU, repeat the inspection proce-
dure from the beginning.

CONNECTOR MEASUREMENT SERVICE 
POINTS

Turn the ignition switch to the "LOCK" (OFF) position 
when connecting and disconnecting the connectors. 
Turn the ignition switch to "ON" when measuring, 
unless there are instructions to the contrary.

HOW TO USE TROUBLESHOOTING/INSPECTION SERVICE POINTS

GENERAL

00-11

IF INSPECTING WITH THE CONNECTOR 
CONNECTED 

<Waterproof Connectors>

AC300881AD

MD998459

Be sure to use special tool harness connector 
(MD998459). Never insert a test probe from the har-
ness side, as this will reduce the waterproof perform-
ance and result in corrosion.

<Ordinary (non-waterproof) Connectors>

AC105598AH

MB992006

Inspect by inserting a test probe from the harness 
side. If the connector is too small to insert a test 
probe (e.g. control unit connector), do not insert it 
forcibly. Use special tool extra fine probe 
(MB992006).

IF INSPECTING WITH THE CONNECTOR 
DISCONNECTED

<When Inspecting a Female Pin>

ACX00865AB

MB991219

Use the special tool inspection harness (MB991219) 
(inspection harness for connector pin contact pres-
sure in the harness set for inspection). The inspec-
tion harness for connector pin contact pressure 
should be used. The test bar should never be forcibly 
inserted, as it may cause a defective contact.

<When Inspecting a Male Pin>

AC300890

CAUTION

At this time, be careful not to short the connector 
pins with the test bars. To do so may damage the 
circuits inside the ECU.
Touch the pin directly with the test bar.

HOW TO USE TROUBLESHOOTING/INSPECTION SERVICE POINTS

GENERAL

00-12

CONNECTOR INSPECTION SERVICE 
POINTS
VISUAL INSPECTION

•

AC300896AB

Connector disconnected or
improperly connected

Stretched or broken wires

Low contact
pressure

Harness wire breakage
at terminal section

Good

Bad

Connector is disconnected or improperly connected

• Connector pins are pulled out

• Due to harness tension at terminal section

• Low contact pressure between male and female 

terminals

• Low connection pressure due to rusted terminals 

or foreign matter lodged in terminals

CONNECTOR PIN INSPECTION

AC300898

If the connector pin stopper is damaged, the terminal 
connections (male and female pins) will not be per-
fect even if the connector body is connected, and the 
pins may pull out of the reverse side of the connec-
tor. Therefore, gently pull the harnesses one by one 
to make sure that no pins pull out of the connector.

CONNECTOR ENGAGEMENT 
INSPECTION

AC300899AB

MB991219

Use the special tool inspection harness (MB991219) 
(connector pin connection pressure inspection har-
ness of the inspection harness set) to inspect the 
engagement of the male pins and female pins. (Pin 
drawing force: 1 N or more)