Mitsubishi Montero (2004+). Manual — part 935

AUTOMATIC TRANSMISSION DIAGNOSIS

TSB Revision

AUTOMATIC TRANSMISSION

23A-315

STEP 4. Check the underdrive clutch system.
(1) Remove the valve body cover and valve body. Refer to

P.23A-563

, Transmission and Transfer Assembly and refer

to GROUP 23B, Transmission

P.23B-14

.

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

clutch oil orifice of the transmission case, and check if the
underdrive clutch piston moves and air pressure is
maintained in that condition.

Q: Is the air pressure maintained?

YES : Go to Step 8.
NO : Go to Step 5.

STEP 5. Check the underdrive clutch.
(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

P.23B-59

,

Underdrive Clutch. Then check the symptom.

Q: Is the symptom eliminated?

YES : The procedure is complete.
NO : Go to Step 9.

STEP 6. Check shift shock.
Q: Does shift shock occur?

YES : Go to Step 7.
NO : Go to Step 8.

ACX02249AB

UNDERDRIVE
CLUTCH OIL
ORIFICE

AC204883 AB

AUTOMATIC TRANSMISSION DIAGNOSIS

TSB Revision

AUTOMATIC TRANSMISSION

23A-316

STEP 7. Using scan tool MB991958, check data list item 11:
TP 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) 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 the idle position, voltage

should measure between 200 and 800 mV.

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

age should measure between 3,800 and 4,900 mV.

(4) Turn the ignition switch to the "LOCK" (OFF) position.
Q: Is the measured voltage between 200 and 800 mV at

idle, and between 3,800 and 4,900 mV in the full-open
position?
YES : Go to Step 9.
NO : Go to Step 8.

STEP 8. Using scan tool MB991958, read the MFI
diagnostic trouble code.
(1) Connect scan tool MB991958 to the data link connector.
(2) Turn the ignition switch to the "ON" position.
(3) Check for MFI diagnostic trouble code.
(4) Turn the ignition switch to the "LOCK" (OFF) position.
Q: Are MFI DTC Nos. of TP sensor system set?

YES : Refer to GROUP 13A, Diagnosis

− Diagnostic

Trouble Code Chart

P.13A-26

.

NO : Go to Step 10.

AC307591 AC

MB991911

MB991824

MB991827

AC307591

DATA LINK

CONNECTOR

AC307591 AC

MB991911

MB991824

MB991827

AC307591

DATA LINK

CONNECTOR

AUTOMATIC TRANSMISSION DIAGNOSIS

TSB Revision

AUTOMATIC TRANSMISSION

23A-317

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-63

.

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 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

ACX02161AD

VALVE BODY ASSEMBLY

AUTOMATIC TRANSMISSION DIAGNOSIS

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AUTOMATIC TRANSMISSION

23A-318

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 the 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-63

. Then

confirm that the symptom is eliminated.

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.

AC307591 AC

MB991911

MB991824

MB991827

AC307591

DATA LINK

CONNECTOR