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 for every driving condition. The ECM 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 CAM phaser error while CMP signal is normally generating and vehicle is driving in 2000 ~ 3000rpm .If the CAM phaser does not move although PCM commands OCV duty cycle PCM determines that a faultexists and a DTC is stored.
Item | Detecting Condition | Possible cause | |
DTC Strategy | ● Determines if the phaser is stuck or has steady-state error | ● Engine Oil ● OCV stuck ● CVVT stuck | |
Enable Conditions | ● CAM signal is normally generating ● Vehicle is on driving (2000 ~ 3000RPM) for 5 minutes. | ||
Thresh old value | Case 1 | ● 5 CAD ＜Cam Actual Position ＜50 CAD ● Duty Cycle〉 90% or Duty Cycle ＜ 10% | |
Case 2 | ● Cam Position error 〉15 CAD (Difference between Actual Postion and Desire Positionis more than 15°) ● Timing Counter > 80 | ||
Diagnosis Time | ● Continuous (within 5min.) | ||
MIL On Condition | ● 2 Driving Cycles | ||
Check DTC Status
Connect scantool to Data Link Connector(DLC).
IG "ON".
Select "Diagnostic Trouble Codes(DTCs)" mode, and then Press F4(DTAL) to check DTC's information from the DTCs menu
Read "DTC Status" parameter.
Is parameter displayed "Present fault"?
▶ Go to "System Inspection" procedure.
▶ Fault is intermittent caused by PCM memory was not cleared after repair. Erase DTC and drive the vehicle to satisfy the enable codition then,go to " System Inspection" procedure.
Visual Inspection
Check oil level is O.K.
Check oil is contaminated.
Has a problem been found ?
▶ Repair or replace as necessary and then, go to " Verification of Vehicle Repair" procedure.
▶ Go to "Component Inspection" procedure.
Check OCV resistance
IG "OFF" and disconnect OCV connector.
Measure resistance between terminal 1 and 2 of OCV. (Component Side)
Resistance (Ω) | 6.7 ~ 7.7 |
Is the measured resistance within specification ?
▶ Go to "Check CAM PHASER with actuation 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.
Check CAM PHASER with actuation test
connect scantool and IG "ON"
Select "CAM PHASER INTAKE BANK 1" on the Actuation Test
Select "OIL CONTROL VALVE" on the Actuation Test
Activates "CAM PHASER INTAKE BANK 1" 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 scan tool and select "Diagnostic Trouble Codes(DTCs)" mode
Press F4(DTAL) and confirm that "DTC Readiness Flag" indicates "Complete". 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.
