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.