P0720

DTC P0720: Malfunction of Secondary Pulley Speed Sensor

















DIAGNOSTIC FUNCTION
TCM determines that the malfunction is present when the secondary pulley speed sensor value changes abruptly or when there is a discrepancy between this sensor and other sensors in sensor reading.

DESCRIPTIONS OF MONITOR METHODS
^ 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 five seconds.
^ 0.1 second after the vehicle speed computed by CVT has dropped abruptly from 20 km/h (12 mph) or more to 5 km/h (3.1 mph) or less.
^ When the secondary pulley speed sensor is found abnormal by comparing the engine speed, primary pulley speed, and vehicle speed.

MONITOR EXECUTION
^ Continuous

MONITOR EXECUTION CONDITIONS (OTHER MONITOR AND SENSOR)

Other Monitor (There is no temporary DTC stored in memory for the item monitored below)
^ P0705: Malfunction of transmission range switch
^ P0712, P0713: Malfunction of the transmission fluid temperature sensor
^ P0715: Malfunction of primary pulley speed sensor
^ P0725: Malfunction of engine speed
^ P0741: Abnormality in lockup function
^ P0746: Abnormality in hydraulic control system function
^ P0841: Abnormality in line pressure sensor function
^ P0868: Secondary pressure drop
^ P1706: Malfunction of throttle signal
^ P1723: Abnormality in speed sensor system function

Sensor (The sensor below is determined to be normal)
^ Transmission range switch
^ Transmission fluid temperature sensor
^ Primary pulley speed sensor
^ Accelerator pedal position sensor

LOGIC FLOW CHARTS (Monitor Sequence)

Logic Flow Charts (Monitor Sequence):

DTC SET CONDITIONS

Check Conditions
^ Transmission range switch position: D.
^ Throttle position: 1/8 or more.
^ Engine speed: 450 r/min or more.
^ Voltage of battery: 9 volts or more.
^ Voltage of battery: 16 volts or less.
^ Transmission range switch: normal.
^ Primary pulley speed sensor: normal.
^ Secondary pulley speed sensor: normal.

Judgement Criteria
^ Secondary pulley speed [primary pulley speed: 1,000 r/min or more]: 150 r/min or less. (5 seconds)
^ Vehicle speed [last vehicle speed: 10 km/h (6.2 mph) or more]: 5 km/h (3.1 mph) or less. (0.1 second)

OBD-II DRIVE CYCLE PATTERN
All the conditions below continue for 6 seconds.
^ Transmission range switch: D
^ Vehicle speed: 10 km/h (6.2 mph) or more
^ Throttle position: 1/8 or more
^ Engine speed: 450 r/min or more
^ Transmission fluid temperature: 20°C (68°F) or more.
^ Transmission fluid temperature: 99°C (210°F) or more.

PROBABLE CAUSES
^ Malfunction of secondary pulley speed sensor
^ Damaged wiring harness and connectors
^ Malfunction of TCM

DIAGNOSTIC PROCEDURE

STEP 1. M.U.T.-III data list
Item 2: Secondary speed sensor signal (Refer to Data List Reference Table.) Data List Reference Table

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

STEP 2. Check the following connector:
^ C-40 TCM connector
^ B-113 Secondary pulley speed sensor connector
^ A-10 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 in the wiring harness between the secondary pulley speed sensor connector and the TCM connector.
Between B-113 secondary pulley speed sensor connector (terminal No.3) and C-40 TCM connector (terminal No.48)

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

STEP 4. Check for open circuit and short to ground in the wiring harness between the secondary pulley speed sensor connector and the TCM connector
Between B-113 secondary pulley speed sensor connector (terminal No.2) and C-40 TCM connector (terminal No.36)

Q: Is the check result normal?
YES: Go to Step 5.
NO: Repair the wiring harness.

STEP 5. Check for open circuit in the wiring harness between the CVT control relay and the secondary pulley speed sensor connector.
Between A-15X CVT control relay (terminal No.3) and B-113 secondary pulley speed sensor connector (terminal No.1)

Q: Is the check result normal?
YES: Go to Step 6.
NO: Repair the wiring harness.

STEP 6. Secondary pulley speed sensor check
Visually check the tip of the sensor for foreign materials or damage.

Q: Is the check result normal?
YES: Go to Step 7.
NO: Repair.

STEP 7. Diagnosis code recheck after replacing the secondary pulley speed sensor

Q: Is the check result normal?
YES: The inspection is complete.
NO: Replace TCM.