Variable Valve Timing-intelligent (VVT-i) system — description and component replacement
Description
1. Variable Valve Timing-intelligent (VVT-i)system is used on all models. The VVT-i system varies intake camshaft timing to produce valve timing that is optimized for the driving conditions. The VVT-i system achieves this by using engine oil pressure to advance or retard the controller on the front end of each intake camshaft.
2. The VVT-i system consists of two CMP sensors, the Powertrain Control Module (PCM), two VVT-i oil control valves and two controllers(intake camshaft sprocket/actuator assemblies).
3. The controller consists of a timing rotor(for the VVT-i sensor), a housing with an impeller-type vane inside it, a lock pin and the actual timing chain sprocket for the intake camshaft. The vane is fixed on the end of the camshaft.
4. The camshaft timing oil control valve isa PCM-controlled device that controls and directs the flow of oil to the advance or retard passages leading to the controller. There is one oil control valve for each camshaft. A spring-loaded spool valve inside the oil controlvalve directs oil pumped into the valve toward either the advance outlet or the retard outlet port, depending on the engine condition.
Oil Control Valve (OCV)
Note: Make sure the ignition key is in the OFF position before before beginning
Replacement
Note: Two OCVs are located on top of the valve cover — one for each camshaft. The intake side OCV is mounted at the rear, the exhaust side OCV is mounted toward the front.
5. Remove the engine cover.
6. Disconnect the electrical connector fromthe camshaft timing oil control valve (see illustration). Remove the engine harness mounting fasteners and move the harness to the side.
i. 6 Identifying camshaft timing oil control valves
A Intake side camshaft timing oil control valve
B Exhaust side camshaft timing oil control valve
7. Remove the camshaft timing oil controlvalve mounting bolt and remove the oil control valve from the valve cover.
8. Installation is the reverse of removal.
Testing
9. Remove the OCV (see previous Steps).
10. Using a Digital Volt Ohm Meter (DVOM) set to measure resistance, measure between the two terminals of the OCV. Resistance of the OCV should be 6.9 to 7.9 Ohms, at roomtemperature (68 degrees-F).
11. Next, apply battery voltage to the OCV to check solenoid functionality. Viewing the OCV from the connector terminals with the valve held upright (connector at the top; bracket facing downward), positive (+) voltage should beapplied to the right-side terminal, and negative (-) voltage at the left. Do not apply the battery voltage for more than a couple seconds.
12. If the OCV does not measure within the specified value or operate properly, replace it.