Mitsubishi Galant (2004+). Manual - part 178

ENGINE CONTROL

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ENGINE AND EMISSION CONTROL

17-3

ENGINE CONTROL

GENERAL DESCRIPTION

M1171000100299

For the accelerator system, an electronic throttle 
actuator control system is utilized, eliminating the 
accelerator cable.

CONSTRUCTION DIAGRAM

AC305917

ACCELERATOR PEDAL
ASSEMBLY
[BUILT-IN ACCELERATOR PEDAL
POSITION SENSOR (APS)]

STOPPER

AB

ENGINE CONTROL

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ENGINE AND EMISSION CONTROL

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SPECIAL TOOL

M1171000600045

TOOL

TOOL NUMBER AND 
NAME

SUPERSESSION APPLICATION

MB991958

A: MB991824
B: MB991827
C: MB991910
D: MB991911
E: MB991914
F: MB991825
G: MB991826

MUT-III sub assembly

A: Vehicle 

Communication 
Interface (V.C.I.)

B: MUT-III USB Cable
C: MUT-III Main Harness 

A (Vehicles with CAN 
communication 
system)

D: MUT-III Main Harness 

B (Vehicles without 
CAN communication 
system)

E: MUT-III Main Harness 

C (for Daimler Chrysler 
models only)

F: MUT-III measurement 

adapter

G: MUT-III Trigger 

Harness

MB991824-KIT
NOTE: G: 
MB991826 MUT-III 
Trigger Harness is 
not necessary 
when pushing 
V.C.I. ENTER key.

Checking diagnostic trouble 
codes

CAUTION

For vehicles with CAN 
communication, use MUT-III 
main harness A to send 
simulated vehicle speed. If 
you connect MUT-III main 
harness B instead, the CAN 
communication does not 
function correctly.

MB991910

MB991826

MB991958

MB991911

MB991914

MB991824

MB991827

MB991825

DO NOT USE

A

B

C

D

E

F

G

DO NOT USE

ENGINE CONTROL

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ENGINE AND EMISSION CONTROL

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ENGINE CONTROL SYSTEM DIAGNOSIS

INTRODUCTION

M1171002000254

If there is a malfunction in the engine control system, 
the accelerator pedal or throttle body may be faulty.

TROUBLESHOOTING STRATEGY

M1171002100284

Use these steps to plan your diagnostic strategy.
If you follow them carefully, you will be sure that you 
have exhausted most of the possible ways to find an 
engine control system fault.
1. Gather information from the customer.

2. Verify that the condition described by the 

customer exists.

3. Find the malfunction by following the Symptom 

Chart.

4. Verify that the malfunction is eliminated.

SYMPTOM CHART

M1171002200292

SYMPTOM PROCEDURES

INSPECTION PROCEDURE 1: Throttle Valve Will Not Fully Open or Close

.

COMMENT
The throttle body or accelerator pedal position sen-
sor (APS) is suspected.

.

TROUBLESHOOTING HINTS (The most likely 
causes for this case:)

• Malfunction of the throttle body.

• Malfunction of the accelerator pedal position sen-

sor (APS).

• Malfunction of the PCM.

DIAGNOSIS

Required Special Tool:

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

• MB991824: V.C.I.

• MB991827: USB Cable

• MB991910: Main Harness A

SYMPTOM

INSPECTION PROCEDURE

REFERENCE PAGE

Throttle Valve Will Not Fully Open or Close

1

P.17-5

Accelerator Pedal Operation Not Smooth (Over 
Acceleration)

2

P.17-7

ENGINE CONTROL

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ENGINE AND EMISSION CONTROL

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STEP 1. Using scan tool MB991958, read the diagnostic 
trouble code (DTC).

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 a green 
color.

(7) Start the MUT-III system on the personal computer.
(8) Turn the ignition switch to the "ON" position.
(9) Check for MFI system diagnostic trouble code (Refer to 

GROUP 13A, MFI Diagnosis - How to Read and Erase 
Diagnostic Trouble Code 

P.13A-5

).

(10)Turn the ignition switch to the "LOCK" (OFF) position, and 

then remove scan tool MB991958 in the reverse order of 
installation.

Q: Is any DTC set?

YES : Refer to GROUP 13A, MFI Diagnosis 

− Diagnostic 

Trouble Code Chart 

P.13A-34

.

NO :  Go to Step 2.

STEP 2. Retest the system.
Q: Does the throttle valve fully open and close?

YES : The procedure is complete.
NO :  Return to Step 1.

AC305412

AB

MB991910

DATA LINK

CONNECTOR

MB991824

MB991827