Code No. P0720: Malfunction of Secondary Pulley Speed Sensor


DIAGNOSTIC FUNCTION



JUDGEMENT CRITERIA



  • The status with the primary pulley speed of 1,000 r/min or more and with the secondary pulley speed of 150 r/min or less continues for 5 seconds.
  • 0.1 seconds after the vehicle speed computed by CVT has dropped abruptly from 20 km/h or more to 5 km/h or less
  • When the secondary pulley speed sensor is found abnormal by comparing the engine speed, primary pulley speed, and vehicle speed

PROBABLE CAUSES



  • Malfunction of secondary pulley speed sensor
  • Damaged wiring harness and connectors
  • Malfunction of CVT-ECU

DIAGNOSTIC PROCEDURE

STEP 1. M.U.T.-III data list
Item 02: Secondary speed sensor signal (Refer to Service Data Table .)

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

STEP 2. Check for open circuit in SGND line between the secondary pulley speed sensor 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 and short to earth in SECS line between the secondary pulley speed sensor 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. Check for open circuit in power supply line between the CVT control relay and the secondary pulley speed sensor connector

Q. Is the check result normal?
Go to Step 5.
Repair the connector(s) or wiring harness.

STEP 5. Secondary pulley speed sensor check
Visually check the tip of the sensor for foreign materials or damage.

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

STEP 6. Diagnosis code recheck after replacing the secondary pulley speed sensor

Q. Is the check result normal?
The inspection is complete.
Replace CVT-ECU.