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 5 seconds.
^ When the vehicle speed computed by CVT has dropped abruptly from 10 km/h (6.2 mph) or more to 5 km/h (3.1 mph) or less, and then the computing value keeps 5 km/h (3.1 mph) or less for 0.5 seconds continuously.

MONITOR EXECUTION
^ transmission range:D
^ Throttle valve opening : 1/8 or more

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)





DTC SET CONDITIONS

Check Conditions
^ Transmission range switch position: D.
^ Throttle position sensor voltage: 1.37 volts or more.
^ Primary pulley speed: 1,000 r/min or more.
^ Secondary pulley speed at 10 millisecond before: 500 r/min or more.
^ Voltage of battery: 9 volts or more.
^ Voltage of battery: 16 volts or less.

Judgment Criteria
^ Secondary pulley speed [primary pulley speed: 1,000 r/min or more]: 150 r/min or less. (5 seconds)
^ Secondary pulley speed [secondary speed at 10 millisecond before: 500 r/min or more]: 260 r/min or less. (0.5 second)

OBD-II DRIVE CYCLE PATTERN
transmission range: D (Drive the vehicle for 10 seconds or more while the accelerator opening angle is 20% or more)

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

DIAGNOSIS

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, 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 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. Diagnostic trouble code recheck after replacing the secondary pulley speed sensor

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