Mitsubishi Grandis. Manual - part 400

HOW TO USE TROUBLESHOOTING/INSPECTION SERVICE POINTS

GENERAL

00-6

• *

2

: For the CAN bus diagnostics table, refer to GROUP 54 

P.54D-16

.

• *

3

: When the MUT-III detects a diagnosis code, its display informs users whether a mechanical problem 

currently exists or whether it existed before but normal operation has been restored. The message for the 
former state identifies it as a "current trouble" and the message for the latter identifies it as a "past 
trouble". However, if MPI and SRS airbag diagnosis codes are set, "current trouble/past trouble" will not 
be displayed. In this case, follow the diagnosis procedure for current trouble.

• *

4

: For how to handle past trouble, refer to .

• *

5

: For how to cope with intermittent malfunctions, refer to   .

2. SYSTEM OPERATION AND SYMPTOM 
VERIFICATION TESTS

If verification of the symptom(s) is difficult, 
procedures for checking operation and verifying 
symptoms are shown.

3. DIAGNOSIS FUNCTION

Details which are different from those in the 
"Diagnosis Function " section are described.

4. DIAGNOSIS CODE CHART

Diagnostic trouble codes and diagnostic items are 
shown.

5. DIAGNOSIS CODE PROCEDURES

Indicates the inspection procedures corresponding to 
each diagnosis code (Refer to How to Use Inspection 
Procedures ).

6. TROUBLE SYMPTOM CHART

If there are trouble symptoms even though the 
MUT-III does not find any diagnosis codes, 
Inspection procedures for each trouble symptom will 
be found by means of this chart.

7. SYMPTOM PROCEDURES

Indicates the inspection procedures corresponding to 
each symptoms classified in the Symptom Chart 
(Refer to How to Use Inspection Procedures ).

8. SERVICE DATA REFERENCE TABLE

Inspection items and normal judgment values have 
been provided in this chart as reference information.

9. ACTUATOR TEST TABLE

The Actuator Test item numbers, inspection items, 
and judgment values have been provided in this 
chart as reference information.

10. CHECK AT ECU TERMINALS

Terminal numbers for the ECU connectors, 
inspection items, and judgment values have been 
provided in this chart as reference information.

11. INSPECTION PROCEDURE BY USING 
AN OSCILLOSCOPE

When there are inspection procedures using an 
oscilloscope, these are described here.

DIAGNOSIS FUNCTION
1. HOW TO READ DIAGNOSIS CODE 

CAUTION

Before connecting or disconnecting the MUT-III, 
turn the ignition switch to the "LOCK" (OFF) 
position.

Connect the MUT-III to the 16-pin diagnosis 
connector, and read the diagnosis code.
NOTE: For details on how to use the MUT-III, refer to 
the "MUT-III operation manual."
1. Ensure that the ignition switch is at the "LOCK" 

(OFF).

2. Start up the personal computer.
3. Connect MUT-III USB cable MB991827 to special 

tool Vehicle Communication Interface (V.C.I.) 
MB991824 and the personal computer.

AC302297

AC310120

AB

MB991827

16-pin

MB991910

MB991824

HOW TO USE TROUBLESHOOTING/INSPECTION SERVICE POINTS

GENERAL

00-7

4. Connect MUT-III main harness A MB991910 to 

the V.C.I.

5. Connect the MUT-III main harness A to the 

diagnosis connector.

6. Turn the V.C.I. power switch to the "ON" position.

NOTE: When the V.C.I. is energized, the V.C.I. 
indicator lamp will be illuminated in a green 
colour.

7. Start the MUT-III system on the personal 

computer and turn the ignition switch to the "ON" 
position.

8. Read the diagnosis code.
9. Disconnecting the MUT-III is the reverse of the 

connecting sequence, making sure that the 
ignition switch is at the "LOCK" (OFF).

2. ERASING DIAGNOSIS CODE

CAUTION

Before connecting or disconnecting the MUT-III, 
turn the ignition switch to the "LOCK" (OFF) 
position.

Connect the MUT-III to the diagnosis connector, and 
erase the diagnosis code. The procedure is the same 
as "How to Read Diagnosis Code ."

3. INPUT SIGNAL CHECK (WHEN USING 
THE MUT-III) <SWS>

CAUTION

Before connecting or disconnecting the MUT-III, 
turn the ignition switch to the "LOCK" (OFF) 
position.

1. Connect the MUT-III to the diagnosis connector, 

and erase the diagnosis code.

2. If the MUT-III buzzer sounds once when each 

switch is operated (ON/OFF), the input signal for 
that switch circuit system is normal.

3. INPUT SIGNAL CHECK (WHEN USING 
A VOLTMETER) <SWS>

1. Use the special tool diagnosis code check 

harness (MB991529) to connect the ETACS 
terminal (terminal 9) and the earth terminals 
(terminals 4 and 5) of the diagnosis connector to 
the voltage meter.

AC302297

AC310120

AB

MB991827

16-pin

MB991910

MB991824

AC302297

AC310120

AB

MB991827

16-pin

MB991910

MB991824

AC310121

MB991529

AB

HOW TO USE TROUBLESHOOTING/INSPECTION SERVICE POINTS

GENERAL

00-8

2. If the needle of the voltage meter flickers once 

when each switch is operated (ON/OFF), the input 
signal for that switch circuit system is normal.

HOW TO USE THE INSPECTION PROCEDURES

The causes of many of the problems occurring in electric circuitry are generally the connectors, components, 
the ECU, the wiring harnesses between connectors, in that order. These inspection procedures 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.

HOW TO USE TROUBLESHOOTING/INSPECTION SERVICE POINTS

GENERAL

00-9

CURRENT TROUBLE

Indicates that the trouble is currently present. Carry 
out troubleshooting as described in the applicable 
inspection procedure.

PAST TROUBLE

Indicates that the trouble is historic, but normal 
operation has been restored. Observe the applicable 
inspection procedure with particular emphasis on 
connector(s) and wiring harness.

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 
inspection 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 
procedure from the beginning.

CONNECTOR MEASUREMENT SERVICE 
POINTS

CAUTION

During diagnosis, a diagnosis code code 
associated with other system may be set when 
the ignition switch is turned on with connector(s) 
disconnected. On completion, confirm all 
systems for diagnosis code(s). If diagnosis 
code(s) are set, erase them all.
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.

AC301965AB

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.