Mitsubishi Galant (2004+). Manual — part 180

AUTO-CRUISE CONTROL

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ENGINE AND EMISSION CONTROL

17-11

AUTO-CRUISE CONTROL SYSTEM DIAGNOSIS

INTRODUCTION TO AUTO-CRUISE CONTROL SYSTEM DIAGNOSIS

M1172003300251

The auto-cruise control system allows driving without
stepping on the accelerator pedal by setting a ran-
dom speed between 40 km/h (25 mph) and 200 km/h
(124 mph). Problems in this system can be investi-
gated by the following methods.

Auto-cruise control system diagnostic
trouble codes

The auto-cruise control system consists of the
powertrain control module (PCM), control switches
and sensors. The control switches and sensors mon-
itor the state of the vehicle. The PCM controls the
throttle valve opening angle in the throttle body in

accordance with the input signals from the switches
and sensors. If the PCM detects a problem on any of
those components, the PCM estimates where the
problem may be occurring, and will set a diagnostic
trouble code. Diagnostic trouble codes cover the
auto-cruise control switch, stoplight switch and PCM.

AUTO-CRUISE CONTROL SYSTEM DIAGNOSTIC TROUBLESHOOTING STRATEGY

M1172002000279

Use these steps to plan your diagnostic strategy. If
you follow them carefully, you will check most of the
possible causes of an auto-cruise control system
problem.
1. Gather information from the customer.
2. Verify that the condition described by the

customer exists.

3. Check the vehicle for any auto-cruise control

system DTC.

4. If you can verify the condition but no auto-cruise

control system DTCs are set, the malfunction may
be intermittent. Refer to GROUP 00, How to Use
Troubleshooting/Inspection Service Points

− How

to Cope with Intermittent Malfunctions

P.00-6

.

5. If you can verify the condition but there are no

auto-cruise control system DTCs, or the system
cannot communicate with scan tool MB991958
(MUT-III sub assembly), refer to

P.17-55

,

Symptom Chart, and find the fault.

6. If there is an auto-cruise control system DTC,

record the number of the code, then erase the
code from PCM memory using the scan tool
MB991958 (MUT-III sub assembly).

7. Re-create the auto-cruise control system DTC set

conditions to see if the same Auto-cruise Control
System DTC will set again.

• If the same Auto-cruise Control System DTC sets

again, perform the diagnostic procedures for the
set code. Refer to

P.17-15

, Auto-cruise Control

System Diagnostic Trouble Code Chart.

AUTO-CRUISE CONTROL

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ENGINE AND EMISSION CONTROL

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AUTO-CRUISE CONTROL SYSTEM DIAGNOSTIC
FUNCTION

M1172004900052

HOW TO CONNECT THE SCAN TOOL (MUT-III).

Required Special Tool:

• MB991958: Scan tool (MUT-III sub assembly)

• MB991824: Vehicle communication interface (V.C.I.)

• MB991827: MUT-III USB cable

• MB991910: MUT-III main harness A

CAUTION

To prevent damage to scan tool MB991958, always turn the
ignition switch to the "LOCK" (OFF) position before con-
necting or disconnecting scan tool MB991958.
1. Ensure that the ignition switch is at the "LOCK" (OFF)

position.

2. Start up the personal computer.
3. Connect special tool MB991827 to special tool MB991824

and the personal computer.

4. Connect special tool MB991910 to special tool MB991824.
5. Connect special tool MB991910 to the data link connector.
6. Turn the power switch of special tool MB991824 to the "ON"

position.
NOTE: When special tool MB991824 is energized, special
tool MB991824 indicator light will be illuminated in green
color.

7. Start the MUT-III system on the personal computer.

NOTE: Disconnecting scan tool MB991958 is the reverse of
the connecting sequence, making sure that the ignition
switch is at the "LOCK" (OFF) position.

AC305412

AB

MB991910

DATA LINK

CONNECTOR

MB991824

MB991827

AUTO-CRUISE CONTROL

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ENGINE AND EMISSION CONTROL

17-13

HOW TO READ AND ERASE DIAGNOSTIC
TROUBLE CODES

Required Special Tool:

• MB991958: Scan tool (MUT-III sub assembly)

• MB991824: V.C.I.

• MB991827: MUT-III USB cable

• MB991910: MUT-III main harness A

CAUTION

To prevent damage to scan tool MB991958, always turn the
ignition switch to the "LOCK" (OFF) position before con-
necting or disconnecting scan tool MB991958.

NOTE: If the battery voltage is low, diagnostic trouble codes
will not be set. Check the battery if scan tool MB991958
does not display.

1. Connect scan tool MB991958 to the data link connector.
2. Turn the ignition switch to the "ON" position.
3. Depress the "CRUISE" (MAIN) switch to illuminate the

"CRUISE" indicator light in the combination meter.

4. Use scan tool MB991958 to read auto-cruise control system

diagnostic trouble codes.

5. Turn the ignition switch to the "LOCK" (OFF) position and

then back to "ON" again.

6. Use scan tool MB991958 to erase auto-cruise control

system diagnostic trouble codes.

7. Turn the ignition switch to the "LOCK" (OFF) position.
8. Disconnect scan tool MB991958.

HOW TO READ DATA LIST

Required Special Tool:

• MB991958: Scan tool (MUT-III sub assembly)

• MB991824: V.C.I.

• MB991827: MUT-III USB cable

• MB991910: MUT-III main harness A

AC305412

AB

MB991910

DATA LINK

CONNECTOR

MB991824

MB991827

AUTO-CRUISE CONTROL

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ENGINE AND EMISSION CONTROL

17-14

CAUTION

To prevent damage to scan tool MB991958, always turn the
ignition switch to the "LOCK" (OFF) position before con-
necting or disconnecting scan tool MB991958.
1. Connect scan tool MB991958 to the data link connector.
2. Turn the ignition switch to the "ON" position.
3. Carry out inspection by means of the data list. If there is an

abnormality, check and repair the chassis harnesses and
components. (Refer to

P.17-66

, Data List Reference Table).

4. Re-check using scan tool MB991958 to be sure that the

abnormal readings have returned to normal because of the
repairs.

5. Erase the diagnostic trouble codes.
6. Turn the ignition switch to the "LOCK" (OFF) position.
7. Disconnect scan tool MB991958.
8. Start the engine again and do a test drive to confirm that the

problem is eliminated.

HOW TO DIAGNOSE THE CAN BUS LINE

Required Special Tools:

• MB991958: Scan tool (MUT-III Sub Assembly)

• MB991824: V.C.I.

• MB991827: MUT-III USB cable

• MB991910: MUT-III main harness A

CAUTION

To prevent damage to scan tool MB991958, always turn the
ignition switch to the "LOCK" (OFF) position before con-
necting or disconnecting scan tool MB991958.
1. Connect scan tool MB991958 to the data link connector.
2. Turn the ignition switch to the "ON" position.
3. Select "CAN bus diagnosis" from the start-up screen.
4. When the vehicle information is displayed, confirm that it

matches the vehicle.

• If they match, go to step 8.

• If not, go to step 5.

5. Select "view vehicle information" button.
6. Input the vehicle information and press "OK".
7. When the vehicle information is displayed, confirm again

that it matches the vehicle.

• If they match, go to step 8.

• If not, go to step 5.

8. Press the "OK" button.
9. When the options are displayed, choose the desired options

(mark the check) and then select "OK".

AC305412

AB

MB991910

DATA LINK

CONNECTOR

MB991824

MB991827

AC305412

AB

MB991910

DATA LINK

CONNECTOR

MB991824

MB991827