Mitsubishi Grandis. Manual - part 856
TROUBLESHOOTING <A/T>
AUTOMATIC TRANSMISSION (FF)
23A-91
STEP 4. Hydraulic pressure test
Measure the hydraulic pressure of the underdrive
clutch when the selector lever is at the L range.
OK: Refer to
.
Q: Is the check result normal?
YES :
Go to Step 7.
NO :
Go to Step 5.
STEP 5. Engine-A/T-ECU replacement
(1) Replace the engine-A/T-ECU.
(2) Test drive the vehicle.
(3) Verify that the condition described by the
customer exists.
Q: Does a malfunction take place again?
YES :
Go to Step 6.
NO :
The inspection is complete.
STEP 6. Valve body disassembly, cleaning, check
and assembly
(1) Check the bolts for looseness and the O-ring,
solenoid valves, springs and valve body for
damage.
Replace the valve body assembly if the damages
are thought to be irreparable.
(2) Test drive the vehicle.
(3) Verify that the condition described by the
customer exists.
Q: Does a malfunction take place again?
YES :
Go to Step 7.
NO :
The inspection is complete.
STEP 7. Oil pump check
(1) If the damage is in the oil pump assembly,
replace the oil pump assembly.
(2) Test drive the vehicle.
(3) Verify that the condition described by the
customer exists.
Q: Is the check result normal?
YES :
Go to Step 8.
NO :
The inspection is complete.
STEP 8. Underdrive clutch check
(1) Check the facing for seizure and the piston seal
ring for damage and interference with the
retainer.
(2) Test drive the vehicle.
(3) Verify that the condition described by the
customer exists.
Q: Is the check result normal?
YES :
The inspection is complete.
NO :
Repair or replace the underdrive clutch.
INSPECTION PROCEDURE 4: Does not move backward
COMMENTS ON TROUBLE SYMPTOM
If the vehicle does not move backward when the
selector lever is shifted to R range while the engine is
idling, the cause is probably abnormal pressure of
the reverse clutch and low-reverse brake or a
malfunction of the reverse clutch, low-reverse brake,
or valve body.
POSSIBLE CAUSES
• Abnormal reverse clutch pressure
• Abnormal low-reverse brake pressure
• Malfunction of low-reverse solenoid valve
• Malfunction of the reverse clutch
• Malfunction of low-reverse brake
• Malfunction of valve body
• Malfunction of the engine-A/T-ECU
DIAGNOSIS
STEP 1. MUT-III actuator test
Item 01: Low-reverse solenoid valve
OK: Operating sound can be heard.
Q: Is the check result normal?
YES :
Go to Step 2.
NO :
Replace the low-reverse solenoid valve.
STEP 2. Hydraulic pressure test
Measure the hydraulic pressure for reverse clutch
and low-reverse brake when the selector lever is at
the R range (Refer to
).
OK: Refer to
.
Q: Is the check result normal?
YES :
Go to Step 5.
NO :
Go to Step 3.