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DTC P264B: Valve Lift Sensor Rationality
 
 
 
 
CIRCUIT OPERATION
  • A power voltage of 5 V is applied to the variable valve lift sensor from the ECM terminal VLS5.
  • The power voltage is grounded to the ECM terminal VLSE from the variable valve lift sensor.
  • The sensor signal is inputted to the ECM terminal VLS from the variable valve lift sensor output terminal.
 
 
TECHNICAL DESCRIPTION
  • The variable valve lift sensor converts valve lift amount to voltage signal, and then sends it to the ECM.
  • The ECM uses this signal to control the valve lift mount.
 
 
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)
  • Variable valve lift system monitor
Sensor (The sensor below is determined to be normal)
  • Not applicable
 
 
DTC SET CONDITIONS <Range/Performance problem - correlation>
Logic Flow Chart
Check Condition
  • More than 0.2 seconds have passed since the engine starting sequence was completed.
Judgment Criterion
  • The difference between the virtual control angle and the actual control angle, which is calculated from the variable valve lift sensor output signal, exceeds 3°.
noteVirtual control angle: The value which the valve lift ECU has calculated in accordance with the variable valve lift sensor output signal (the ECM communicates via VLC-CAN).
noteActual control angle: The value calculated from the variable valve lift sensor output
 
 
DTC SET CONDITIONS <Range/Performance problem>
Logic Flow Chart
Check Condition
  • More than 0.2 seconds have passed since the engine starting sequence was completed.
Judgment Criterion
  • The minimum valve lift learning value is less than 0.5 volt.
or
  • The minimum valve lift learning value is higher than 1.4 volts.
 
 
FAIL-SAFE AND BACKUP FUNCTION
  • The valve lift is fixed to maximum. Otherwise, deenergizes the motor.
  • V.V.T. phase angle is set to most retarded position.
 
 
OBD-II DRIVE CYCLE PATTERN
  • Refer to Diagnostic Function - OBD-II Drive Cycle - Pattern 23 .
 
 
TROUBLESHOOTING HINTS (The most likely causes for this code to be stored are: )
  • Variable valve lift sensor circuit harness damage, or connector damage.
  • The variable valve lift sensor improperly installed
  • Variable valve lift sensor failed.
  • Defective variable valve lift system.
  • Valve lift ECU failed.
  • ECM failed.
 
 
 
DIAGNOSIS
STEP 1. Check whether the variable valve lift sensor is installed properly.
Is the sensor installed properly?
Go to Step 2.
Repair it. Then go to Step 7.
 
STEP 2. Check of harness damage in VLS5 line between ECM connector and variable valve lift sensor connector.
Is the harness wire in good condition?
Go to Step 3.
Repair the connector(s) or wiring harness. Then go to Step 7.
 
STEP 3. Check of open circuit and harness damage in VLSE line between ECM connector and variable valve lift sensor connector.
Is the harness wire in good condition?
Go to Step 4.
Repair the connector(s) or wiring harness. Then go to Step 7.
 
STEP 4. Check of harness damage in VLS line between ECM connector and variable valve lift sensor connector.
Is the harness wire in good condition?
Go to Step 5.
Repair the connector(s) or wiring harness. Then go to Step 7.
 
STEP 5. Variable valve lift mechanism check
Refer to GROUP 11A, On-vehicle Service - Variable Valve Lift Mechanism Check .
Is the check result normal?
Go to Step 6.
Repair it. Then go to Step 7.
 
STEP 6. Check the trouble symptoms.
(1) Carry out test drive with the drive cycle pattern. Refer to Diagnostic Function - OBD-II Drive Cycle - Pattern 23 .
(2) Check the diagnostic trouble code (DTC).
Is DTC P264B stored?
Replace the ECM (Refer to Removal and Installation ). Then go to Step 7.
It can be assumed that this malfunction is intermittent. Refer to GROUP 00, How to Use Troubleshooting/Inspection Service Points - How to Cope with Intermittent Malfunctions .
 
STEP 7. Test the OBD-II drive cycle.
(1) Carry out a test drive with the drive cycle pattern. Refer to Diagnostic Function - OBD-II Drive Cycle - Pattern 23 .
(2) Check the diagnostic trouble code (DTC).
Is DTC P264B stored?
Retry the troubleshooting.
The inspection is complete.