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DTC P0746: Abnormality in Hydraulic Control System Function
 
 
 
 
DIAGNOSTIC FUNCTION
If the pulley ratio, which is calculated according to the primary pulley speed and the secondary pulley speed, exceeds the standard value, the TCM determines that the line pressure is abnormal.
 
 
DESCRIPTIONS OF MONITOR METHODS
  • The ratio between the primary pulley speed and the secondary pulley speed is 2.55 or more for 0.2 seconds, or 3.35 or more for 0.1 second.
 
 
MONITOR EXECUTION
  • Transmission range: D, R or B
  • Primary speed: 500 r/min or more
  • Acceleration: -0.05G or more
  • Engine speed: 450 r/min 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
  • P0715: Malfunction of primary pulley speed sensor
  • P0720: Abnormality in output speed sensor
  • P0791: Malfunction of the secondary pulley speed sensor
  • U0001: Malfunction of CAN communication
  • U0100: CAN time-out error (engine)
Sensor (The sensor below is determined to be normal)
  • Transmission range switch
  • Primary pulley speed sensor
  • Output speed sensor
  • Secondary pulley speed sensor
 
 
LOGIC FLOW CHARTS (Monitor Sequence)
 
 
DTC SET CONDITIONS
Check Conditions
  • Transmission range switch position: D, R or B.
  • Engine speed: 450 r/min or more.
  • Primary pulley speed: 500 r/min or more.
  • Acceleration: -0.05G or more
Judgment Criteria
  • Pulley ratio (primary pulley speed/secondary pulley speed) more than 2.55 for 0.2 second.
  • Pulley ratio (primary pulley speed/secondary pulley speed) more than 3.35 for 0.1 second.
 
 
OBD-II DRIVE CYCLE PATTERN
The vehicle is driven for at least 10 seconds with the accelerator opening angle at 20% or more.
 
 
PROBABLE CAUSES
  • Malfunction of the valve body assembly (Faulty line pressure solenoid valve)
  • Malfunction of the transaxle assembly
 
 
DIAGNOSIS
STEP 1. Check the following connector
  • CVT assembly connector
Check the terminals for a contact status problem and internal short circuit.
Is the check result normal?
Go to Step 2.
Repair the defective connector.
 
STEP 2. Measure the output wave pattern of the line pressure solenoid valve at TCM connector (PLLS terminal).
(1) Connect the CVT assembly connector.
(2) Selector lever position: P range.
(3) Engine: Idling
(4) Connect an oscilloscope, and measure the voltage between TCM connector PLLS terminal and body ground.
OK: A wave pattern such as the one shown on (Check Procedure Using an Oscilloscope) should be output, and the maximum value should be 11 V or more and the minimum value should be 1 V or less. There should be no noise in the output wave pattern.
Is the check result normal?
Go to Step 3.
Refer to diagnostic trouble code No.P0962: Line Pressure Solenoid Valve (short to ground) , or diagnostic trouble code No.P0963: Line Pressure Solenoid Valve (open circuit/ short to power supply) .
 
STEP 3. Symptom recheck after erasing diagnostic trouble code
(1) Erase the diagnostic trouble code.
(2) Turn the ignition switch to the LOCK (OFF) position, and then wait for one minute. Then drive the vehicle until the engine has been warmed up.
(3) Check if the diagnostic trouble code is stored.
Is the diagnostic trouble code stored?
Go to Step 4.
Intermittent malfunction (Refer to GROUP 00 - How to Cope with Intermittent Malfunctions .).
 
STEP 4. CVT belt inspection.
Check the appearance of the CVT belt. (Refer to On-vehicle Service – CVT Belt Inspection)
Is the CVT belt normal?
Replace valve body assembly. (Refer to ).
Replace the transaxle assembly (Refer to ).