P0077

DTC P0077 Intake Valve Control Solenoid Circuit High (Bank 1)




COMPONENT LOCATION

GENERAL DESCRIPTION
The CVVT (Continuously Variable Valve Timing) system built on the camshaft helps the engine decrease the exhaust gas and increase engine power and fuel economy by changing the valve open/close timing of the intake camshaft continuously. The oil control valve, the main control part of the CVVT, changes the direction of the oil path through the CVVT by the duty control of the PCM and changes the open and close timing of the intake and exhaust valves.

DTC DESCRIPTION
PCM sets DTC P0077 if the PCM detects that the oil control valve control circuit is open or short to battery.

DTC Detection Condition:

Schematic Diagram:

Signal Waveform:

MONITOR DTC STATUS
1. Connect scan tool and select "Diagnostic Trouble Codes(DTCs)" mode
2. Press F4(DTAL) to select DTC information from the DTCs menu
3. Confirm that "DTC Readiness Flag" indicates "Complete". If not, drive the vehicle within conditions noted in the freeze frame data or enable conditions




4. Read "DTC Status" parameter
5. Is parameter displayed "History (Not Present) fault"?

NOTE
1. History (Not Present) fault: DTC occurred but has been cleared.
2. Present fault: DTC is occurring at present time.

YES: Fault is intermittent caused by poor contact in the sensor's and/or PCM'S connector or was repaired and PCM memory was not cleared. Thoroughly check connectors for looseness, poor connection, bending, corrosion, contamination, deterioration, or damage. Repair or replace as necessary and then go to "Verification of Vehicle Repair" procedure.

NO: Go to "Component Inspection" procedure

COMPONENT INSPECTION
1. Ignition "OFF".
2. Disconnect oil control valve connector.




3. Measure resistance between terminals 1 and 2 of the solenoid connector (Component side).
4. Is resistance within specification?

YES: Go to next step as below.

NO: Check oil control valve for contamination, deterioration, or damage. Substitute with a known-good solenoid and check for proper operation. If the problem is corrected, replace solenoid and then go to "Verification of Vehicle Repair" procedure

CONTROL CIRCUIT INSPECTION
1. Ignition "OFF".
2. Disconnect oil control valve and PCM connectors.
3. Ignition "ON".
4. Measure voltage between terminals 1 of the intake valve control solenoid connector and chassis ground.
Specification: Below 0.5 V

5. Is voltage within specification?

YES: Go to "Terminal and Connector Inspection" procedure.

NO: Repair short to power in harness and go to "Verification of Vehicle Repair" procedure.

TERMINAL AND CONNECTOR INSPECTION
1. Many malfunctions in the electrical system are caused by poor harness(es) and terminals. 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: Check for poor connection between PCM and component: backed out terminal, improper mating, broken locks or poor terminal to wire connection. Repair as necessary 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 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.
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.