The CVVT (Continuously Variable Valve Timing) system is installed to the chain sprocket of the intake camshaft. This system controls the intake camshaft to provide the optimal valve timing. The PCM controls the Oil Control Valve(OCV), based on the signals output from mass air flow, throttle position and engine coolant temperature. The CVVT controller regulates the intake camshaft angle using oil pressure through the OCV. As result, the relative position between the camshaft and the crankshaft becomes optimal, and the engine torque improves, fuel economy improves, exhaust emissions decrease under overall driving conditions.
PCM monitors OCV stuck while cam signal is normally generating and Valve cleaning is not in progress .If the CAM Acutal Position is too high or low and Difference between Cam Actual Positionand Desired Position is higher than 20° PCM determines that a fault exists and a DTC is stored.
Item | Detecting Condition | Possible cause | |
DTC Strategy | ● Determines if oil control valve is stuck | ● Oil Pressure ● OCV seizure | |
Enable Conditions | ● Valve cleaning not in progress ● CAM signal is normally generating | ||
Thresh old value | Case 1 | ● Cam Actual Position＞ 50 CAD or Difference between CAM Actual Position and Desired Position ＞ 20 CAD | |
Case 2 | ● Cam Actual Position ＜ 5 CAD or Difference between CAM Actual Position and Desired Position ＞ 20 CAD | ||
Diagnosis Time | ● Continuous (Within 1min.) | ||
MIL On Condition | ● 2 driving Cycle | ||
Resistance (Ω) | 6.7 ~ 7.7 |
Fig.1. Idle - normal Condition
Fig. 2.Acceleration
Check DTC Status
Connect scantool to Data Link Connector(DLC).
IG "ON".
Select "DTC" button, and then Press "DTC Status" to check DTC's information from the DTCs menu.
Read "DTC Status" parameter.
Is parameter displayed "Present fault"?
▶ Go to "Terminal and Connector inspection" procedure.
▶ Fault is intermittent caused by PCM memory was not cleared after repair. Erase DTC and drive the vehicle to satisfy the enable condition then, go to "System Inspection" procedure.
Many malfunctions in the electrical system are caused by poor harness and terminal condition. Faults can also be caused by interference from other electrical systems, and mechanical or chemical damage.
Thoroughly check connectors for looseness, poor connection, bending, corrosion, contamination, deterioration, or damage.
Has a problem been found?
▶ Repair as necessary and go to "Verification of Vehicle Repair" procedure
▶ Go to " Power Circuit Inspection " as follow
IG "OFF" and disconnect OCV connector.
IG "ON" ＆ ENG "OFF".
Measure voltage between power terminal of OCV harness connector and chassis ground.
Be careful not to change the connectors for Bank1 and Bank2
Specification : B+
Is the measured voltage within specification ?
▶ Go to " Control Circuit Inspection " procedure.
▶ Check that Fuse between Main Relay and OCV is open.
▶ Check open between main relay and OCV.
▶ Check short to ground between Main Relay and OCV.
▶ Repair or replace as necessay go to "Verification of Vehicle Repair " procedure.
IG "OFF" and disconnect OCV connector.
IG "ON" ＆ ENG "OFF".
Measure voltage between control terminal of OCV harness connector and chassis ground.
Specification : Approx. below 1V
Is the measured voltage within specification ?
▶ Go to "System Inspection" procedure.
▶ Repair or replace as necessary and then go to "Verification of Vehicle Repair" procedure.
Check oil level is O.K.
Check oil is contaminated.
Check that any oil leakage is occurred around CVVT system.
Has a problem been found ?
▶ Repair or replace as necessary and then, go to " Verification of Vehicle Repair" procedure.
▶ Go to "Component Inspection" procedure
IG "OFF" and disconnect OCV connector.
Measure resistance between power and signal terminals of OCV. (Component Side)
Specification : 6.7 ~ 7.7 Ω
Is the measured resistance within specification ?
▶ Go to "Check CAM PHASER with acuation test" as follows.
▶ Substitute with a known - good OCV and check for proper operation. If the problem is corrected, replace OCV and go to "Verification of Vehicle Repair" procedure.
Connect scantool and IG "ON".
Select "CAM PHASER INTAKE BANK 2" on the Actuation Test.
Select "OIL CONTROL VALVE" on the Actuation Test.
Activates "CAM PHASER INTAKE BANK 2" by pressing "STRT(F1)" key.
Activates "OIL CONTROL VALVE" by pressing "STRT(F1)" key.
Repeat this procedure 4 or 5 times to ensure CAM PHASER and intake valve control solenoid reliability.
Has a problem been found ?
▶ Substitute with a known - good CVVT or OCV and check for proper operation.
If the problem is corrected, replace CVVT or OCV and go to "Verification of Vehicle Repair" procedure.
▶ Fault is intermittent. Drive the vehicle to meet the enable condition for the DTC. and Go to "Verification of Vehicle Repair" procedure.
After a repair, it is essential to verify that the fault has been corrected.
Connect scantool and select "DTC" button.
Press "DTC Status" button and confirm that "DTC Readiness Flag" indicates "Completed". If not, drive the vehicle within conditions noted in the freeze frame data or enable conditions
Read "DTC Status" parameter
Is parameter displayed "History(Not Present) fault"?
▶ System performing to specification at this time. Clear the DTC
▶ Go to the applicable troubleshooting procedure.
