Mitsubishi Galant (2004+). Manual - part 688

AUTOMATIC TRANSAXLE DIAGNOSIS

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AUTOMATIC TRANSAXLE

23A-303

INSPECTION PROCEDURE 10: Early or Late Shifting in All Gears

COMMENT
If all shift points are early or late while driving, the
cause is probably a malfunction of the output shaft
speed sensor, TP sensor or a solenoid valve.

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

• Malfunction of the output shaft speed sensor

• Malfunction of the TP sensor

• Malfunction of each solenoid valve

• Abnormal line pressure

• Malfunction of the valve body

• Malfunction of the PCM

DIAGNOSIS

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

STEP 1. Using scan tool MB991958, check data list item 23:
Output Shaft Speed Sensor.

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) Start the engine.

(3) Set scan tool MB991958 to the data reading mode.

• Item 23: Output Shaft Speed Sensor.

• When driving at constant speed of 50km/h (31mph),

the display should be "1,400

− 1,700 r/min" (Gear

range: 3rd gear).

(4) Turn the ignition switch to the "LOCK" (OFF) position.
Q: Is the sensor operating properly?

YES : Go to Step 2.
NO : Refer to

P.23A-91

, DTC 23: Output shaft speed

sensor system.

AC305412

MB991910

DATA LINK

CONNECTOR

MB991824

MB991827

AUTOMATIC TRANSAXLE DIAGNOSIS

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AUTOMATIC TRANSAXLE

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STEP 2. Using scan tool MB991958, check data list item 11:
TP Sensor.

(1) Connect scan tool MB991958 to the data link connector.
(2) Turn the ignition switch to the "ON" position.
(3) Set scan tool MB991958 to the data reading mode.

• Item 11: TP Sensor.

• With the throttle valve in idle position, voltage should

measure between 300 and 700 mV.

• With the throttle valve in full-open position, voltage

should measure 4,000 mV or more.

(4) Turn the ignition switch to the "LOCK" (OFF) position.
Q: Is the measured voltage between 300 and 700 mV at

idle, and 4,000 mV or more at the full-open position?
YES : Go to Step 3.
NO : Check the TP sensor. Refer to GROUP13A <2.4L

Engine>, Diagnostic Trouble Code Procedures

P.13A-156

P.13A-166

, DTCs P0122, P0123: TP

Sensor System or refer to GROUP13B <3.8L
Engine>, Diagnostic Trouble Code Procedures

P.13B-156

P.13B-166

, DTCs P0122, P0123: TP

Sensor System. Then check the symptom.

STEP 3. Using scan tool MB991958, check data list.

(1) Connect scan tool MB991958 to the data link connector.
(2) Start the engine.

AC305412

MB991910

DATA LINK

CONNECTOR

MB991824

MB991827

AC305412

MB991910

DATA LINK

CONNECTOR

MB991824

MB991827

AUTOMATIC TRANSAXLE DIAGNOSIS

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(3) Set scan tool MB991958 to the data reading mode for

following items.

a. Item 31: Low-Reverse Solenoid Valve Duty Percent
b. Item 32: Underdrive Solenoid Valve Duty Percent

c. Item 33: Second Solenoid Valve Duty Percent

d. Item 34: Overdrive Solenoid Valve Duty Percent

• Check that the values shown below are displayed

when each data list item is entered.

(4) Turn the ignition switch to the "LOCK" (OFF) position.
Q: Are the solenoid valves operating properly?

YES : Go to Step 4.
NO : Go to Step 6.

STEP 4. Adjust the line pressure.

Adjust the line pressure. Refer to

P.23A-42

, Line Pressure

Adjustment. Then check the symptom.
Q: Is the symptom eliminated?

YES : The procedure is complete.
NO : Go to Step 5.

STEP 5. Disassemble and clean the valve body.

Check the O-ring installation bolts for looseness and the valve
body for damage. Repair or replace the faulty parts. Refer to
GROUP 23B, Valve Body

P.23B-79

Replace the valve body assembly if the damages are thought
to be irreparable. Then check the symptom.
Q: Is the symptom eliminated?

YES : The procedure is complete.
NO : Go to Step 7.

STEP 6. Replace each solenoid valve.

Replace the faulty solenoid valve with a new one.
Q: Is the symptom eliminated?

YES : The procedure is complete.
NO : Go to Step 7.

DRIVING CONDITION

DATA LIST ITEM
31

Driving at constant speed of 10 km/h (6.2 mph) in 1st gear 0%

100%

Driving at constant speed of 30 km/h (19 mph) in 2nd gear 100%

100%

Driving at constant speed of 50 km/h (31 mph) in 3rd gear 100%

100%

Driving at constant speed of 50 km/h (31 mph) in 4th gear 100%

100%

AC001860 AB

VALVE
BODY
ASSEMBLY

AC001869 AB

OVERDRIVE
SOLENOID
VALVE

LOW-
REVERSE
SOLENOID
VALVE

VALVE
BODY
ASSEMBLY

UNDERDRIVE
SOLENOID
VALVE

SECOND
SOLENOID
VALVE

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AUTOMATIC TRANSAXLE

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STEP 7. Replace the PCM.
Q: Is the symptom eliminated?

YES : The procedure is complete.
NO : Start over at Step 1.

INSPECTION PROCEDURE 11: Early or Late Shifting in Some Gears

COMMENT
If some of the shift points are early or late when driv-
ing, the cause is probably a malfunction of the valve
body, or it is due to the characteristics of the
INVECS-II system but is not an abnormality.

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

• Malfunction of the valve body

• Malfunction of the PCM

DIAGNOSIS

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

STEP 1. Using scan tool MB991958, check actuator test
item 14: INVECS-II Cancel Command.

CAUTION

(3) Set scan tool MB991958 to the actuator test mode.

• Item14: INVECS-II Cancel Command.

• Drive the vehicle and confirm the gear shifting corre-

spond to the standard shift line of the shift pattern
diagram. Refer to

P.23A-3

(4) Turn the ignition switch to the "LOCK" (OFF) position.
Q: Does the gear shifting correspond to the standard shift

line of the shift pattern diagram?
YES : The symptom is due to characteristics of the

INVECS-II system, but is not abnormal.

NO : Go to Step 2.

AC305412

MB991910

DATA LINK

CONNECTOR

MB991824

MB991827

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