P1740

DTC P1740: Malfunction of Lockup/Select Switching Solenoid Valve

SOLENOID VALVE SYSTEM CIRCUIT
Refer to DTC P0740. P0740

DIAGNOSTIC FUNCTION
TCM detects abnormal operation of the lockup/select switching solenoid valve.

JUDGEMENT CRITERIA
^ The status with the switching solenoid valve ON and with the monitoring value OFF is detected for 0.2 second.
^ The status with the switching solenoid valve OFF and with the monitoring value ON is detected for 0.2 second.

PROBABLE CAUSES
^ Malfunction of valve body assembly (Faulty lockup/select switching solenoid valve)
^ Damaged wiring harness and connectors
^ Malfunction of TCM

DIAGNOSTIC PROCEDURE

STEP 1. M.U.T.-III data list
Item 36: LU/SEL change over SOL. output

Item 37: LU/SEL change over SOL. monitor

OK: Check that the output and monitor do not differ greatly.

Q: Is the check result normal?
YES: Intermittent malfunction
NO: Go to Step 2.

STEP 2. Check the following connector:
^ B-08 CVT assembly connector
^ C-41 TCM connector
^ A-09 Intermediate connector

Check the terminals for a contact status problem and internal short circuit.

Q: Is the check result normal?
YES: Go to Step 3.
NO: Repair the defective connector.

STEP 3. Check for open circuit and short to ground in the wiring harness between the TCM connector and the CVT assembly connector.
Between C-41 TCM connector (terminal No.14) and B-08 CVT assembly connector (terminal No.4)

Q: Is the check result normal?
YES: Go to Step 4.
NO: Repair the wiring harness.

STEP 4. Lockup/select switching solenoid valve single unit check

Q: Is the check result normal?
YES: Go to Step 5.
NO: Replace the valve body assembly.

STEP 5. Symptom recheck after erasing diagnosis code

Q: Is the check result normal?
YES: Intermittent malfunction
NO: Replace TCM.