Mitsubishi Montero (2002-2004). Manual — part 974

SYMPTOM PROCEDURES <AUTOMATIC TRANSMISSION>

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SYMPTOM PROCEDURES

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STEP 3. Check the hydraulic pressure (for low-reverse
brake).
Measure the hydraulic pressure for low-reverse brake when the
selector lever is at the "R" range, and check if the hydraulic
pressure is within the standard value. Refer to

P.23Ab-15

,

Hydraulic Pressure Test.
Q: Is the hydraulic pressure within the standard value?

YES : Go to Step 4.
NO : Go to Step 5.

STEP 4. Check the reverse clutch system and low-reverse
brake system.
(1) Remove the valve body cover and valve body. Refer to

P.23Aa-37

, Transmission and Transfer Assembly and refer

to GROUP 23B, Transmission

P.23B-18

.

(2) Blow 108 kPa (15psi) compressed air into the reverse

clutch oil orifice of the Transmission case. Then check if the
reverse clutch piston moves and air pressures are
maintained in that condition. Repeat for the low-reverse
brake.

Q: Are the reverse clutch, low-reverse brake or both air

pressures maintained?
YES : Go to Step 5.
NO : Go to Step 6.

STEP 5. Disassemble and clean the valve body.
Check the O-ring installation bolts for looseness and valve
body for damage. Repair or replace the faulty parts. Refer to
GROUP 23B, Valve Body

P.23B-80

.

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

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

STEP 6. Check the reverse clutch, low-reverse brake or
both. Remove the Transmission.
Check the facing for seizure and the piston seal ring for dam-
age and interference with the retainer. Repair or replace the
faulty parts. Refer to GROUP 23B, Transmission

P.23B-18

,

Reverse and Overdrive Clutch

P.23B-67

. Then check the

symptom.
Q: Is the symptom eliminated?

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

ACX02249AC

REVERSE
CLUTCH OIL
ORIFICE

LOW-REVERSE
BRAKE OIL
ORIFICE

ACX02161AD

VALVE BODY ASSEMBLY

AC204883

REVERSE
CLUTCH

LOW-REVERSE
BRAKE

AC

SYMPTOM PROCEDURES <AUTOMATIC TRANSMISSION>

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SYMPTOM PROCEDURES

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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 4: Does not Move (Forward or Backward)

.

COMMENT
If the vehicle does not move forward or backward
when the selector lever is shifted to any position
while the engine is idling, the cause is probably
abnormal line pressure, or a malfunction of the
power train, oil pump or valve body.

.

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

• Abnormal line pressure

• Malfunction of the power train

• Malfunction of the oil pump

• Malfunction of the valve body

• Low A/T fluid level

• Malfunction of the PCM

DIAGNOSIS

STEP 1. Check the hydraulic pressure.
Measure the hydraulic pressure of each element when the
transmission is in 1st, 2nd or reverse. Check if each hydraulic
pressure is within the standard value. Refer to

P.23Ab-15

,

Hydraulic Pressure Test. If some elements are within the stan-
dard value and some are not, recheck the symptom.
Q: Are all pressures within the standard value?

YES : Check transmission fluid level and condition. If not

OK, repair or replace as necessary, then recheck
symptom. If OK, go to Step 3.

NO : Go to Step 2.

STEP 2. Disassemble and clean the valve body.
Check the O-ring installation bolts for looseness and 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 repair possible and the symptom eliminated?

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

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VALVE BODY ASSEMBLY

SYMPTOM PROCEDURES <AUTOMATIC TRANSMISSION>

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SYMPTOM PROCEDURES

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STEP 3. Check the transmission power train components.
Disassemble the transmission and check the planetary carrier
and output shaft, etc. Repair or replace the damaged parts.
Refer to GROUP 23B, Transmission

P.23B-18

, Low-Reverse

Annulus Gear

P.23B-72

. Then check the symptom.

Q: Is the symptom eliminated?

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

STEP 4. Replace the oil pump.
(1) Remove the transmission.
(2) Replace the oil pump (Oil pump cannot be repaired). Refer

to GROUP 23B, Transmission

P.23B-18

. Then check the

symptom.

Q: Is the symptom eliminated?

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

STEP 5. Replace the PCM.
Q: Is the symptom eliminated?

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

INSPECTION PROCEDURE 5: Engine Stalls when Moving Selector Lever from "N" to "D" or "N" to "R"

.

COMMENT
If the engine stalls when the selector lever is shifted
from "N" to "D" or "R" range while the engine is idling,
the cause is probably a malfunction of the engine
system, torque converter clutch solenoid valve, valve
body or torque converter (torque converter clutch
malfunction).

.

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

• Malfunction of the engine system

• Malfunction of the torque converter clutch sole-

noid

• Malfunction of the valve body

• Malfunction of the torque converter (Malfunction

of the torque converter clutch)

• Malfunction of the PCM

AC204883AJ

PLANETARY
CARRIER

DIRECT
PLANETARY
CARRIER

AC204883 AD

SYMPTOM PROCEDURES <AUTOMATIC TRANSMISSION>

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SYMPTOM PROCEDURES

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DIAGNOSIS

STEP 1. Check the engine system.
Refer to GROUP 13A, Diagnosis

− Trouble Symptom Chart −

When the engine is hot, it stalls at idle

P.13Ab-26

.

Q: Is the inspection result good?

YES : Go to Step 2.
NO : Repair or replace the engine components.

STEP 2. Replace the torque converter clutch solenoid
valve.
Replace the torque converter clutch solenoid valve. Refer to
GROUP 23B, Valve Body

P.23B-80

. Then check the symptom.

Q: Is the symptom eliminated?

YES : The procedure is complete.
NO : Go to Step 3.

STEP 3. Disassemble and clean the valve body.
Check the O-ring installation bolts for looseness and 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 repair possible and the symptom eliminated?

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

STEP 4. Replace the torque converter assembly.
(1) Remove the transmission.
(2) Replace the torque converter assembly. Refer to GROUP

23B, Transmission

P.23B-18

. Then check the symptom.

Q: Is the symptom eliminated?

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

STEP 5. Replace the PCM.
Q: Is the symptom eliminated?

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

ACX02161AE

ACX02161AD

VALVE BODY ASSEMBLY

AC204883 AE