Code No. P0740: Malfunction of Lockup Solenoid Valve


DIAGNOSTIC FUNCTION



JUDGEMENT CRITERIA



PROBABLE CAUSES



  • Malfunction of valve body assembly (Faulty lockup solenoid valve)
  • Damaged wiring harness and connectors
  • Malfunction of CVT-ECU

DIAGNOSTIC PROCEDURE

STEP 1. M.U.T.-III data list

  • Item 31: Lockup solenoid output current
  • Item 30: Lockup solenoid monitoring current
OK: Check if the output current and monitoring current differ largely.

Q. Is the check result normal?
Intermittent malfunction
Go to Step 2.

STEP 2. Check for open circuit and short to earth in LULS line between the CVT-ECU connector and the CVT assembly connector

Q. Is the check result normal?
Go to Step 3.
Repair the connector(s) or wiring harness.

STEP 3. Lockup solenoid valve single unit check
Refer to .

Q. Is the check result normal?
Go to Step 4.
Replace the valve body assembly.

STEP 4. Symptom recheck after erasing diagnosis code

Q. Is the check result normal?
Intermittent malfunction
Replace CVT-ECU.