Mitsubishi Galant 9G. Manual — part 544

AUTOMATIC TRANSAXLE DIAGNOSIS

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AUTOMATIC TRANSAXLE

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LOGIC FLOW CHARTS (Monitor Sequence) <DTC 46 (P0736)>

Yes

Engine speed

START

Yes

Transmission fluid temperature
sensor voltage < 4.5 V

There is only one transmission
range switch signal

Yes

> 450 r/min

OPG-B

> 350 r/min

IPG-A

> 0 r/min

Continuous failure for 4 secs.

Good

END

OPG-B

: Output speed

(output shaft speed sensor)

Yes

Malfunction

Shift change is finished

IPG-A

: Input speed

(input shaft speed sensor)

: Reverse g

ear ratio

AC205248

Timer start

Timer > 2 secs.

Voltage of battery > 10 V

Shift stage commanded
by A/T ECM is reverse

Yes

× N

OPG-B

- 200 < N

IPG-A

< I

× N

OPG-B

+ 200

Shift stage commanded
by PCM is reverse

0.5 sec.

100

1 sec.

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DTC SET CONDITIONS <DTC 46 (P0736)>

Check Conditions

• Engine speed: 450 r/min or more.

• Output speed: 100 r/min or more.

• Shift stage: reverse gear.

• Input speed: more than 0 r/min.

• Transmission fluid temperature sensor voltage:

4.5 volts or less.

• Voltage of battery: 10 volts or more.

• Transmission range switch rationality: only one

signal.

• Time after shift changing finish: 0.5 second or

more.

Judgement Criteria

• Output speed: [(input speed + 200 r/min) /

reverse gear ratio] or more. (1 second)

• Output speed: [(input speed - 200 r/min) / reverse

gear ratio] or less. (1 second)

• If DTC 46 (P0736) is set consecutively four times,

the transaxle is locked into 3rd gear as a fail-safe
measure, and the "N" range light flashes once
per second.

OBD-II DRIVE CYCLE PATTERN <DTC 46
(P0736)>

Start the engine, and drive in "R" range at 15 km/h (9
mph) or more for 10 seconds.

TROUBLESHOOTING HINTS (THE MOST
LIKELY CAUSES FOR THIS CODE TO BE
SET ARE:)

• Malfunction of the input shaft speed sensor

• Malfunction of the output shaft speed sensor

• Malfunction of the PCM

• Malfunction of the underdrive clutch retainer

• Malfunction of the transfer drive gear or driven

gear

• Malfunction of the low-reverse brake system

(DTC 41 or DTC 46)

• Malfunction of the underdrive clutch system (DTC

41, DTC 42, or DTC 43)

• Malfunction of the second brake system (DTC 42

or DTC 44)

• Malfunction of the overdrive clutch system (DTC

43 or DTC 44)

• Malfunction of the reverse clutch system (DTC

46)

• Electrical noise generated

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

AUTOMATIC TRANSAXLE DIAGNOSIS

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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 set?

YES <DTC 22 set> : Refer to

P.23A-69

, DTC 22: Input

Shaft Speed Sensor System.

YES <DTC 23 set> : Refer to

P.23A-90

, DTC 23: Output

Shaft Speed Sensor System.

YES <DTC 31 set> : Refer to

P.23A-187

, DTC 31:

Low-Reverse Solenoid Valve System.

YES <DTC 32 set> : Refer to

P.23A-200

, DTC 32:

Underdrive Solenoid Valve System.

YES <DTC 33 set> : Refer to

P.23A-211

, DTC 33: Second

Solenoid Valve System.

YES <DTC 34 set> : Refer to

P.23A-222

, DTC 34:

Overdrive Solenoid Valve System.

NO : Go to Step 2.

STEP 2. Check the hydraulic pressure.
Each hydraulic pressure of the elements below, which DTCs
indicate, should be within the standard value.

P.23A-29

• DTC 41: Underdrive clutch and low-reverse brake.

• DTC 42: Underdrive clutch and second brake

• DTC 43: Underdrive clutch and overdrive clutch

• DTC 44: Overdrive clutch and second brake

• DTC 46: Reverse clutch and low-reverse brake

Q: Does the hydraulic pressures meet the standard value

range?
YES : Go to Step 5.
NO <out of the range in one place> : Go to Step 4.
NO <out of the range in all places> : Go to Step 3.

STEP 3. 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 4.

AC305412

MB991910

DATA LINK

CONNECTOR

MB991824

MB991827

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STEP 4. 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-80

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 6.

STEP 5. Replace the PCM.
(1) Replace the PCM.
(2) Test drive the vehicle.
(3) Check for A/T diagnostic trouble code.
Q: Were any A/T DTCs set?

YES : Go to Step 6.
NO : The procedure is complete.

STEP 6. Overhaul the A/T.
(1) Replace the following parts.

• If DTC 41, DTC 42, or DTC 43 are set individually or in a

group, replace the underdrive clutch. Refer to GROUP
23B, Underdrive Clutch and Input Shaft

P.23B-60

• If DTC 43 or DTC 44 are set individually or in a group,

replace the overdrive clutch. Refer to GROUP 23B,
Reverse and Overdrive Clutch

P.23B-62

• If DTC 46 is set, replace the reverse clutch. Refer to

GROUP 23B, Reverse and Overdrive Clutch

P.23B-62

• If DTC 41 or DTC 46 are set individually or in a group,