Mitsubishi Montero Sport (2004+). Manual - part 698

AUTOMATIC TRANSMISSION DIAGNOSIS

TSB Revision

AUTOMATIC TRANSMISSION

23A-357

INSPECTION PROCEDURE 7: Shift Shock when Shifting from "N" to "R" and Long Delay

COMMENT
If abnormal shock or delay of two seconds or more
occurs when the selector lever is shifted from "N" to
"R" range while the engine is idling, the cause is
probably abnormal reverse clutch pressure or
low-reverse brake pressure, or a malfunction of the
reverse clutch, low-reverse brake, valve body or TP
sensor.

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

• Abnormal reverse clutch pressure

• Abnormal low-reverse brake pressure

• Malfunction of the low-reverse solenoid valve

• Malfunction of the reverse clutch

• Malfunction of the low-reverse brake

• Malfunction of the valve body

• Malfunction of the TP sensor

• Malfunction of the PCM

DIAGNOSIS

Required Special Tool:

• MB991958: Scan Tool (MUT-III Sub Assembly)

• MB991824: V.C.I.

• MB991827: MUT-III USB Cable

• MB991911: MUT-III Main Harness B

STEP 1. Using scan tool MB991958, check actuator test
item 01: Low-Reverse Solenoid Valve.

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) Set scan tool MB991958 to actuator test mode.

• Item 01: Low-Reverse Solenoid Valve.

• An audible clicking or buzzing should be heard when

the low-reverse solenoid valve is energized.

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

YES : Go to Step 2.
NO : Repair or replace the low-reverse solenoid valve.

Refer to GROUP 23B, Valve Body

P.23B-67

. Then

confirm that the symptom is eliminated.

AK303629AB

MB991911

MB991827

MB991824

16-PIN

AUTOMATIC TRANSMISSION DIAGNOSIS

TSB Revision

AUTOMATIC TRANSMISSION

23A-358

STEP 2. Check when shift shock occurs.
Q: When does the shift shock occur?

When engaging from "N" to "R" : Go to Step 3.
When the vehicle starts moving : Go to Step 7.

STEP 3. Check the hydraulic pressure (for reverse clutch).

Measure the hydraulic pressure for reverse clutch when the
selector lever is at the "R" range. Check if the hydraulic pres-
sure is within the standard value. Refer to

P.23A-26

, Hydraulic

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

YES : Go to Step 4.
NO : Go to Step 9.

STEP 4. 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. Check if the hydraulic pres-
sure is within the standard value. Refer to

P.23A-26

, Hydraulic

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

YES : Go to Step 5.
NO : Go to Step 9.

STEP 5. Check the reverse clutch system and low-reverse

brake system.
(1) Remove the valve body cover and valve body. Refer to

P.23A-453

, Transmission and Transfer Assembly and refer

to GROUP 23B, Transmission

P.23B-19

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

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

Q: Are both air pressures maintained?

YES : Go to Step 6.
NO : Go to Step 9.

ACX02249AC

REVERSE
CLUTCH OIL
ORIFICE

LOW-REVERSE
BRAKE OIL
ORIFICE

AUTOMATIC TRANSMISSION DIAGNOSIS

TSB Revision

AUTOMATIC TRANSMISSION

23A-359

STEP 6. Check the reverse clutch and low-reverse brake.

(1) Remove the transmission assembly.
(2) Check the facing for seizure and the piston seal ring for

damage and interference with the retainer. Repair or
replace the faulty parts. Refer to GROUP 23B,
Transmission

P.23B-19

, Reverse and Overdrive Clutch

P.23B-54

. Then retest the system.

Q: Is the symptom eliminated?

YES : The procedure is complete.
NO : Go to Step 10.

STEP 7. Check shift shock.
Q: Does shift shock occur sometimes?

YES : Go to Step 8.
NO : Go to Step 9.

STEP 8. Using scan tool MB991958, check data list item 11:
TP Sensor.

CAUTION

• Item 11: TP Sensor.

• With the throttle valve in the idle position, voltage

should measure between 535 and 735 mV.

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

age should measure between 4,500 and 5,500 mV.

(4) Turn the ignition switch to the "LOCK" (OFF) position.
Q: Is the measured voltage between 535 and 735mV at idle,

and between 4,500 and 5,500 mV in the full-open
position?
YES : Go to Step 9.
NO : Check the TP sensor. Refer to GROUP 13A,

On-vehicle Service

P.13A-890

. Then check the

symptom.

AC103774

LOW-REVERSE
BRAKE

REVERSE CLUTCH

AK303629AB

MB991911

MB991827

MB991824

16-PIN

AUTOMATIC TRANSMISSION DIAGNOSIS

TSB Revision

AUTOMATIC TRANSMISSION

23A-360

STEP 9. 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-67

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 10.

STEP 10. Replace the PCM.
Q: Is the symptom eliminated?

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

INSPECTION PROCEDURE 8: Shift Shock when Shifting from "N" to "D," "N" to "R" and Long Delay

COMMENT
If abnormal shock or delay of two seconds or more
occurs when the selector lever is moved from "N" to
"D" range and from "N" to "R" range while the engine
is idling, the cause is probably abnormal line pres-
sure or a malfunction of the transmission oil pump or
valve body.

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

• Abnormal line pressure

• Malfunction of the transmission oil pump

• Malfunction of the valve body

• Malfunction of the PCM

DIAGNOSIS

STEP 1. Check the hydraulic pressure.
(1) 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.23A-26

, Hydraulic Pressure Test.

(2) If some elements pressure are within the standard value

and some are not, recheck the symptom.

Q: Are all hydraulic pressures within the standard value?

YES : Go to Step 3.
NO : Go to Step 2.

STEP 2. Adjust line pressure.

Adjust line pressure. Refer to

P.23A-39

, Line Pressure Adjust-

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

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

AC004272

VALVE BODY ASSEMBLY

Content .. 696 697 698 699 ..