Code No.P1786 (P0741) Damper clutch system (stuck off)
OPERATION
The ECU engages and disengages the damper clutch (incorporated in the torque converter) by operating the DCC solenoid valve in response to driving conditions.
DIAGNOSIS CODE SET CONDITIONS
If the damper clutch solenoid valve drive duty ratio of 100% for 4 seconds or more continuously is detected 4 times, and the status occurs 2 drive cycles consecutively, when the damper clutch starts operating, the diagnosis code No. P1786 (P0741) is set.
PROBABLE CAUSES
- Malfunction of input shaft speed sensor
- Damaged harness wires and connectors
- Malfunction of the A/T-ECU <4M4>
- Malfunction of the engine-A/T-ECU <6G7>
- Malfunction of damper clutch solenoid valve
- Malfunction of valve body assembly
- Malfunction of torque converter
|
|
STEP 1. M.U.T.-III diagnosis code
|
|
|
If diagnosis code P1786 (P0741) is set, the input shaft speed sensor may be defective.
|
|
|
Q.
Is diagnosis code P1766 (P0715) set?
|
|
|
 Refer to diagnosis code P1766 (P0715): Input shaft speed sensor system  .
|
|
|
|
|
|
 Go to Step 2.
|
|
|
|
|
|
STEP 2. M.U.T.-III diagnosis code
|
|
|
If diagnosis code P1786 (P0741) is set, the damper clutch solenoid valve may be defective.
|
|
|
Q.
Is diagnosis code P1778 (P0743) set?
|
|
|
Refer to diagnosis code P1778 (P0743): Damper clutch solenoid valve system .
|
|
|
|
|
|
Go to Step 3.
|
|
|
|
|
|
STEP 3. M.U.T.-III data list
|
|
|
- Item 17: Damper clutch solenoid valve duty ratio (Refer to data list reference table ).
- Item 10: Damper clutch slip amount (Refer to data list reference table ).
|
|
|
Q.
Is the check result normal?
|
|
|
Go to Step 6.
|
|
|
|
|
|
Go to Step 4.
|
|
|
|
|
|
STEP 4. Hydraulic pressure test
|
|
|
Measure the torque converter hydraulic pressure. (Refer to ).
|
|
|
OK: Refer to Hydraulic Pressure Test .
|
|
|
Q.
Is the check result normal?
|
|
|
Go to Step 6.
|
|
|
|
|
|
Go to Step 5.
|
|
|
|
|
|
STEP 5. Adjust the line pressure and recheck the diagnosis code.
|
|
|
(1)Adjust the line pressure (Refer to ).
|
|
|
(2)Test drive the vehicle.
|
|
|
(3)Check the diagnosis code.
|
|
|
Q.
Is the diagnosis code set?
|
|
|
Go to Step 7.
|
|
|
|
|
|
The inspection is complete.
|
|
|
|
|
|
STEP 6. Replace the A/T-ECU <4M4> or engine-A/T-ECU <6G7> and then recheck the diagnosis code.
|
|
|
(1)Replace the A/T-ECU <4M4> or engine-A/T-ECU <6G7>.
|
|
|
(2)Test drive the vehicle.
|
|
|
(3)Check the diagnosis code.
|
|
|
Q.
Is the diagnosis code set?
|
|
|
Go to Step 7.
|
|
|
|
|
|
The inspection is complete.
|
|
|
|
|
|
STEP 7. Disassemble, clean and assemble the valve body and recheck the diagnosis code.
|
|
|
(1)Check the mounting bolts for looseness, and the O-ring, solenoid valve and valve body for damage.
Replace the valve body assembly if the damages are thought to be irreparable.
|
|
|
(2)Test drive the vehicle.
|
|
|
(3)Check the diagnosis code.
|
|
|
Q.
Is the diagnosis code set?
|
|
|
Check the torque converter and replace it if necessary.
|
|
|
|
|
|
The inspection is complete.
|
|
|
|