Code No.P1796: Idle Neutral Control Function Failure <Vehicles with Idle Neutral Control>


DIAGNOSTIC FUNCTION



JUDGMENT CRITERIA




  • [(Difference between the engine speed and the turbine speed) - Target slip speed] is greater than 300 r/min for 10 seconds.

PROBABLE CAUSES



  • Malfunction of turbine speed sensor
  • Damaged wiring harness and connectors
  • Malfunction of forward clutch

DIAGNOSTIC PROCEDURE

STEP 1. Check other diagnosis codes.

Q. Are other diagnosis codes set?
Carry out the appropriate troubleshooting.
Go to Step 2.

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

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

STEP 3. Check for open circuit in SGND line between the CVT assembly connector and the CVT-ECU connector.

Q. Is the check result normal?
Go to Step 4.
Repair the connector(s) or wiring harness.

STEP 4. Diagnosis code recheck

Q. Is the diagnosis code set?
Go to Step 5.
Intermittent malfunction.

STEP 5. Turbine speed sensor check
Disassemble the CVT and visually check the tip of the sensor for foreign materials or damage.

Q. Is the check result normal?
Go to Step 6.
Repair or replace.

STEP 6. Check for open circuit or short to earth in wiring harness between the CVT assembly connector and the turbine speed sensor connector.

Q. Is the check result normal?
Go to Step 7.
Replace the valve body harness.

STEP 7.Forward clutch check


Check for facing scorching, failed piston seal rings, retainer interference, etc.

Q. Is the check result normal?
Replace the turbine speed sensor.
Repair or replace the forward clutch.