Mitsubishi Galant (2004+). Manual - part 678

AUTOMATIC TRANSAXLE DIAGNOSIS

TSB Revision

AUTOMATIC TRANSAXLE

23A-263

STEP 8. Replace the valve body.

(1) Replace the valve body. Refer to GROUP 23B, Transaxle 

P.23B-10

.

(2) Test drive the vehicle.
(3) Check for A/T diagnostic trouble code.
Q: Is DTC 52 set?

YES : Replace the torque converter. Refer to GROUP 23B, 

Transaxle 

P.23B-10

.

NO :  The procedure is complete.

DTC 53 (P0742): Torque Converter Clutch is Stuck On

.

DESCRIPTIONS OF MONITOR METHODS

• With PCM signal for no lock-up engagement, if 

vehicle speed equals or exceeds specified value, 
accelerator is ON, and torque converter slip 
amount is below specified value, PCM judges 
that torque converter clutch is stuck ON.

.

MONITOR EXECUTION

• Continuous

.

MONITOR EXECUTION CONDITIONS (Other 
monitor and Sensor)

Other Monitor (There is no temporary DTC stored 

in memory for the item monitored below)

• DTC 21 (P0335): Crankshaft position sensor mal-

function

• DTC 22 (P0715): Input shaft speed sensor mal-

function

• DTC 23 (P0720): Output shaft speed sensor mal-

function

• DTC 52 (P0741): Torque converter clutch system 

malfunction (Stuck OFF)

• DTC 36 (P0743): Torque converter clutch sole-

noid malfunction

• P0122: Throttle position sensor (main) malfunc-

tion (Low input)

• P0123: Throttle position sensor (main) malfunc-

tion (High input)

• P0222: Throttle position sensor (sub) malfunction 

(Low input)

• P0223: Throttle position sensor (sub) malfunction 

(High input)

• P2135: Throttle position sensor (main and sub) 

range/performance problem

• P0638: Throttle actuator control motor circuit 

range/performance problem

• P0642: Throttle position sensor power supply

• P1601: Communication malfunction (Between 

PCM and throttle actuator control module)

• P0606: PCM main processor malfunction

• P2108: Throttle actuator control module proces-

sor malfunction

• P2100: Throttle actuator control motor circuit 

(Open)

• P2101: Throttle actuator control motor magneto 

malfunction

• P2102: Throttle actuator control motor circuit 

(Shorted low)

• P2103: Throttle actuator control motor circuit 

(Shorted high)

• P2122: Accelerator pedal position sensor (main) 

circuit low input

• P2123: Accelerator pedal position sensor (main) 

circuit high input

• P2127: Accelerator pedal position sensor (sub) 

circuit low input

• P2128: Accelerator pedal position sensor (sub) 

circuit high input

• P2138: Accelerator pedal position sensor (main 

and sub) range/performance problem

Sensor (The sensor below is determined to be 

normal)

• Input shaft speed sensor

• Output shaft speed sensor

• Crankshaft position sensor

• Torque converter clutch solenoid

• Throttle position sensor

• Accelerator pedal position sensor

.

AC001860 AB

VALVE
BODY
ASSEMBLY

AUTOMATIC TRANSAXLE DIAGNOSIS

TSB Revision

AUTOMATIC TRANSAXLE

23A-264

LOGIC FLOW CHARTS (Monitor Sequence)

.

DTC SET CONDITIONS

Check Conditions

• Throttle position sensor voltage: 1.5 volts or 

more.

• Output speed: 1,000 r/min or more.

• Solenoid status: OFF.

• Transmission range switch position: D, 3, 2 or L.

• Time after lock up clutch release: 5 seconds or 

more.

AC205239

START

END

Transmission range 
switch position is in 
D, 3, 2 or L range

TCC solenoid is in
OFF steady state

TCC in disengagement area

Timer start

TCC in disengagement area

Timer > 5 secs.

V

THROTTLE

 > 1.5 V

N

OPG-B

 > 1,000 r/min

N

E

 - 5 < N

IPG-A

 < N

E

 + 5

Continuous failure 
for 10 secs.

Good

Malfunction

Yes

No

Yes

No

Yes

No

Yes

No

Yes

No

Yes

No

Yes

No

Yes

No

Yes

No

N

E

 : 

Engine speed

N

OPG-B 

: Output speed

            (output shaft speed sensor)

N

IPG-A 

: Input speed

           (input shaft speed sensor)

V

THROTTLE

 : Throttle position sensor 

                  output voltage

AUTOMATIC TRANSAXLE DIAGNOSIS

TSB Revision

AUTOMATIC TRANSAXLE

23A-265

Judgement Criteria

• Calculated slip (engine speed - input speed): 5 

r/min or more. (10 seconds)

• Calculated slip (engine speed - input speed): -5 

r/min or less. (10 seconds)

.

OBD-II DRIVE CYCLE PATTERN
Start the engine, and drive at 30 km/h (19 mph) for 
30 seconds. Then stop the vehicle, and turn "LOCK" 
(OFF) the ignition switch. After that, restart the 
engine, and drive again at 30 km/h (19 mph) for 30 
seconds.

.

TROUBLESHOOTING HINTS (The most likely 
causes for this code to be set are:)

• Malfunction of the torque converter clutch sole-

noid valve

• Malfunction of the valve body

• Damaged harness or connector

• 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, read the A/T 
diagnostic trouble code.

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) Check for A/T diagnostic trouble code.
(4) Turn the ignition switch to the "LOCK" (OFF) position.
Q: Is DTC 36 set?

YES : Refer to 

P.23A-233

, DTC 36: Torque Converter 

Clutch Solenoid Valve System.

NO :  Go to Step 2.

AC305412

AB

MB991910

DATA LINK

CONNECTOR

MB991824

MB991827

AUTOMATIC TRANSAXLE DIAGNOSIS

TSB Revision

AUTOMATIC TRANSAXLE

23A-266

STEP 2. Using scan tool MB991958, check data list item 52: 
Amount of Torque Converter Clutch Slippage.

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

• Item 52: Torque Converter Clutch Amount of Slippage.

• Driving at a constant speed of 60 km/h (37 mph), the 

display should be "

−10 to 10 r/min."

• If the accelerator pedal is released, the display on 

the scan tool changes (50 km/h (31 mph) and less).

(4) Turn the ignition switch to the "LOCK" (OFF) position.
Q: Is the torque converter clutch slippage within the 

specified range?
YES : It can be assumed that this malfunction is intermittent. 

Refer to GROUP 00, How to Use 
Troubleshooting/Inspection Service Points 

− How to 

Cope with Intermittent Malfunction 

P.00-6

.

NO :  Go to Step 3.

STEP 3. Replace the PCM.
(1) Replace the PCM.
(2) Test drive the vehicle.
(3) Check for A/T diagnostic trouble code.
Q: Is DTC 53 set?

YES : Go to Step 4.
NO :  The procedure is complete.

STEP 4. Replace the valve body.

(1) Replace the valve body. Refer to GROUP 23B, Transaxle 

P.23B-10

.

(2) Test drive the vehicle.
(3) Check for A/T diagnostic trouble code.
Q: Is DTC 53 set?

YES : Replace the Torque Converter. Refer to GROUP 23B, 

Transaxle 

P.23B-10

.

NO :  The procedure is complete.

AC305412

AB

MB991910

DATA LINK

CONNECTOR

MB991824

MB991827

AC001860 AB

VALVE
BODY
ASSEMBLY