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DTC P2648: Variable Valve Lift Control Motor Coil Open
 
 
 
 
CIRCUIT OPERATION
Controls the current that is applied from the valve lift ECU terminal VLMV, VLMU and VLMW to the variable valve lift control motor.
 
 
TECHNICAL DESCRIPTION
  • The valve lift ECU rotates the worm shaft when the three-phase coil of the variable valve lift control motor is energized sequentially and variably.
 
 
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
Logic Flow Chart
Check Condition
  • More than 0.2 seconds have passed since the engine starting sequence was completed.
Judgment Criterion
  • The ECM has received malfunction from the valve lift ECU via VLC-CAN.
  • Contents of malfunction which the valve lift ECU detects
    1. All the terminal voltages at U, V and W phases are 7 volts or less.
 
 
FAIL-SAFE AND BACKUP FUNCTION
  • Deenergizes the variable valve lift control motor.
 
 
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: )
  • Open variable valve lift control motor circuit, harness damage, or connector damage.
  • Variable valve lift control motor failed.
  • Valve lift ECU failed.
 
 
DIAGNOSIS
STEP 1. Check the variable valve lift control motor.
Refer to Variable Valve Lift Control Motor Check .
Does continuity exist?
Go to Step 2.
Replace the variable valve lift control motor. Then go to Step 6.
 
STEP 2. Check of open circuit and harness damage in VLMV line between variable valve lift control motor connector and valve lift ECU connector.
Is the harness wire in good condition?
Go to Step 3.
Repair the connector(s) or wiring harness. Then go to Step 6.
 
STEP 3. Check of open circuit and harness damage in VLMU line between variable valve lift control motor connector and valve lift ECU connector.
Is the harness wire in good condition?
Go to Step 4.
Repair the connector(s) or wiring harness. Then go to Step 6.
 
STEP 4. Check of open circuit and harness damage in VLMW line between variable valve lift control motor connector and valve lift ECU connector.
Is the harness wire in good condition?
Go to Step 5.
Repair the connector(s) or wiring harness. Then go to Step 6.
 
STEP 5. 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 P2648 stored?
Replace the valve lift ECU. Then go to Step 6.
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 6. 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 P2648 stored?
Retry the troubleshooting.
The inspection is complete.