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DTC P0730: Incorrect Gear Ratio
 
 
 
 
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
Pulley ratio is more than 2.981 for 0.2 seconds, or more than 3.781 for 0.1 second, while the vehicle is driven at selector lever position D range.
 
 
MONITOR EXECUTION
  • Engine speed: More than 450 r/min.
  • Primary speed: More than 450 r/min.
  • Acceleration: -0.05G or more.
  • Voltage of battery: 10 volts or more.
 
 
MONITOR EXECUTION CONDITIONS (OTHER MONITOR AND SENSOR)
Other Monitor (There is no temporary DTC stored in memory for the item monitored below)
  • Not applicable
Sensor (The sensor below is determined to be normal)
  • Not applicable
 
 
LOGIC FLOW CHARTS (Monitor Sequence)
 
 
DTC SET CONDITIONS
Check Conditions
  • Voltage of battery: 10 volts or more.
  • Transmission range switch position: D.
  • Engine speed: 450 r/min or more.
  • Primary pulley speed: More than 450 r/min
  • Acceleration: -0.05G or more.
Judgment Criteria
  • Pulley ratio (primary pulley speed/secondary pulley speed) more than 3.781 for 0.1 second [2 times (Interval 1 second)].
  • Pulley ratio (primary pulley speed/secondary pulley speed) more than 2.981 for 0.2 second [2 times (Interval: 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 valve body assembly (Faulty line pressure solenoid valve)
  • Malfunction of the CVT assembly
 
 
DIAGNOSIS
Required Special Tools
  • MB992006: Extra fine probe
STEP 1. Scan tool (M.U.T.-IIISE) diagnostic trouble code.
Is diagnostic trouble code No. P0962 or P0963 set?
Carry out the appropriate troubleshooting.
Go to Step 2.
 
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: N.
(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. 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: Malfunction of Line Pressure Solenoid Valve (low input) , or diagnostic trouble code No.P0963: Malfunction of Line Pressure Solenoid Valve (high input) .
 
STEP 3. Symptom recheck after erasing diagnostic trouble code.
Turn the ignition switch to the "LOCK" (OFF) position, and wait for one minute. Then, drive the vehicle for a while and check again.
Is the diagnostic trouble code set?
Replace the CVT assembly.
Intermittent malfunction (Refer to GROUP 00 - How to Cope with Intermittent Malfunctions ).