P1066

P1066-CYLINDER 1 OIL SUPPLY SOLENOID VALVE SWITCH OFF TIME OUT OF RANGE

For a complete wiring diagram, refer to the Wiring Information.





Theory of Operation

MultiAir is an electronically controlled variable intake valve phase and lift system. Unlike conventional intake valve phase and lift system which controls all the cylinder intake valves simultaneously and in the same proportion; MultiAir, through the use of an electronically controlled " hydraulic link" between the camshaft and intake valve, allow for each intake valve to be controlled independently. The valve lift and timing can be adjusted infinitely

The MultiAir valve train has a mechanical camshaft lobe acting on a hydraulic pump located between the camshaft intake lobe and the intake valve. The pump provides oil under pressure to a two-way electro-hydraulic solenoid valve called the Variable Valve Actuator (VVA) Solenoid. The VVA Solenoid is electronically controlled during the specific intake cam lobe event by the Powertrain Control Module (PCM). During the event the VVA Solenoid is commanded to either hold oil pressure or bleed oil. The Variable Valve Actuator (VVA) Solenoid is a normally open solenoid. The PCM provides 12 volts to close the solenoid. The position of the VVA Solenoid determines the intake valve timing and lift. This change on valve action is similar to creating a change in the camshaft lobe profile affecting lift and duration of the valve opening.

- When Monitored:
Engine running.

- Set Condition:
The Powertrain Control Module (PCM) measures the time needed to turn off the VVA Solenoid. When the PCM recognizes that the VVA Solenoids switch off time is too fast or too slow a fault is set. One trip fault.





Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. Pre-Diagnostic Troubleshooting Procedure.

Diagnostic Test

1. ACTIVE DTC

NOTE: If the P1523 DTC is present, diagnose and repair that DTC before continuing with this test procedure.

1. Start the engine and allow it to idle.
2. With a scan tool, read the DTCs.

Is the DTC active at this time?

Yes

- Go To 2

No

- Perform the INTERMITTENT CONDITION diagnostic procedure. Intermittent Condition Test.

2. CHECK THE ENGINE OIL

NOTE: The actuators will not operate if the oil pressure is too low or too high.

1. Check the engine for the following:
- LOW ENGINE OIL
- INCORRECT OIL FILTER THAT DOES NOT MEET OEM SPECIFICATIONS
- OIL DIRTY OR DETERIORATED (Lack of scheduled oil changes)
- CORRECT VISCOSITY AND WEIGHT
- ENGINE OIL CONTAMINATED (i.e., coolant and/or fuel)

Is oil level, type, condition, and filter correct?

Yes

- Go To 3

No

- Correct level/change engine oil and filter as required, consult the service information for correct type and grade of engine oil and repeat test.

3. CHECK OIL PRESSURE / ENGINE MECHANICAL
1. Remove the Oil Pressure Switch and install a mechanical oil pressure gauge.

2. Crank the engine for at least 10 seconds and check the oil pressure at the Oil Pressure Switch location.

Is the oil pressure between 0.8 bar (11.6 psi) and 7.5 bar (108.8 psi)?

Yes

- Replace the Variable Valve Actuator Assembly.
- Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test.

No

- Repair as necessary.
- Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test.