P0028
P0028Component Location:
General Description
The CVVT (Continuously Variable Valve Timing) system is installed on 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.
DTC Description
PCM monitors OCV stuck while cam sinal is normally generating and Valve cleaning is not in progress.
If the CAM Actual Position is too high or low and Difference between Cam Actual Position and Desire Position is higher than 20 ° PCM determines that a fault exists and a DTC is stored.
DTC Detecting Condition:
Specification :
Resistance : 6.7 - 7.7 ohms
Signal Waveform:
Schematic Diagram:
Monitor DTC Status
1. Check DTC Status
1. Connect scantool to Data Link Connector(DLC).
2. IG "ON".
3. Select "Diagnostic Trouble Codes(DTCs)" mode, and then Press F5(INFO) to check DTC's information from the DTCs menu
4. Read "DTC Status" parameter.
5. Is parameter displayed "Present fault"?
YES
a. Go to "Terminal and Connector inspection" procedure.
NO
a. 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.
Terminal and Connector Inspection
1. 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.
2. Thoroughly check connectors for looseness, poor connection, bending, corrosion, contamination, deterioration, or damage.
3. Has a problem been found?
YES - Repair as necessary and go to "Verification of Vehicle Repair" procedure
NO - Go to "Power Circuit Inspection" as follow
Power Supply Circuit Inspection
1. IG "OFF" and disconnect OCV connector.
2. IG "ON" & ENG "OFF".
3. Measure voltage between terminal 2 of OCV harness connector and chassis ground.
CAUTION: Be careful not to change the connectors for B1 and B2
a. Specification : B+
4. Is the measured voltage within specification ?
YES - Go to "Control Circuit Inspection" procedure.
NO
- 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 necessary go to "Verification of Vehicle Repair" procedure.
Control Circuit Inspection
1. IG "OFF" and disconnect OCV connector.
2. IG "ON" & ENG "OFF".
3. Measure voltage between terminal 1 of OCV harness connector and chassis ground.
a. Specification : Approx. below 1 V
4. Is the measured voltage within specification ?
YES - Go to "System Inspection" procedure.
NO - Repair or replace as necessary and then go to "Verification of Vehicle Repair" procedure.
System Inspection
1. Visual Inspection
1. Check oil level and oil cleanness is O.K.
2. Check OCV is contaminated.
3. Check that any oil leakage is occurred around OCV.
4. Has a problem been found ?
YES - Repair or replace as necessary and then, go to "Verification of Vehicle Repair" procedure.
NO - Go to "Component Inspection" procedure
Component Inspection
1. OCV Inspection
1. IG "OFF" & Disconnect OCV connector.
2. Measure resistance between terminal 1 and 2 of OCV connector (Component Side)
a. Specification :
Resistance : 6.7 - 7.7 ohms
3. Is the measured resistance within specifications ?
YES - Go to "Check CAM PHASER with actuation test" as follow.
NO
- 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.
2. Check CAM PHASER with actuation test
1. connect scantool and IG "ON"
2. Select "CAM PHASER INTAKE BANK 2" on the Actuation Test
3. Select "OIL CONTROL VALVE" on the Actuation Test
4. Activate "CAM PHASER INTAKE BANK 2" by pressing "STRT(F1)" key
5. Activate "OIL CONTROL VALVE" by pressing "STRT(F1)" key
6. Repeat this procedure 4 or 5 times to ensure CAM PHASER and intake valve control solenoid reliability
7. Has a problem been found ?
YES
- 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.
NO - Fault is intermittent. Drive the vehicle to meet the enable condition for the DTC. and Go to "Verification of Vehicle Repair" procedure.
Verification of Vehicle Repair
After a repair, it is essential to verify that the fault has been corrected.
1. Connect scan tool and select "Diagnostic Trouble Codes(DTCs)" mode
2. Press F5(INFO) and confirm that "DTC Readiness Flag" indicates "Complete". If not, drive the vehicle within conditions noted in the freeze frame data or enable conditions
3. Read "DTC Status" parameter
4. Is parameter displayed "History(Not Present) fault"?
YES - System performing to specification at this time. Clear the DTC
NO - Go to the applicable troubleshooting procedure.