P1044

P1044-IMPLAUSIBLE DATA FROM CYLINDER 4 OIL SUPPLY SOLENOID VALVE RECEIVED

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:
With the engine running and no battery or ASD Relay DTCs active.

- Set Condition:
The Powertrain Control Module (PCM) detects that the VVA Solenoid feedback current level is implausible. One trip fault.





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

Diagnostic Test

1. ACTIVE DTC
1. Start the engine and allow it to idle.

WARNING:
When the engine is operating, do not stand in direct line with the fan. Do not put your hands near the pulleys, belts, or fan. Do not wear loose clothing. Failure to follow these instructions can result in possible serious or fatal injury.

2. With the scan tool, select View DTCs.

Is the DTC Active at this time?

Yes

- Go To 2

No

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

2. VVA SOLENOID 4
1. Turn the ignition off.
2. Gain access to the VVA Solenoid 4.
3. Disconnect the VVA Solenoid 4 harness connector.
4. Using an Ohm meter, measure the resistance across the terminals of the VVA Solenoid.

Is the resistance between 0.5 and 1.0 Ohms?

Yes

- Go To 3

No

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

3. CHECK FOR EXCESSIVE RESISTANCE IN THE (N38) VVA SOLENOID 4 SIGNAL CIRCUIT
1. Disconnect the PCM C2 harness connector.
2. Measure the resistance of the (N38) VVA Solenoid 4 Signal circuit between the VVA Solenoid 4 harness connector and the PCM C2 harness connector.

Is the resistance below 5.0 Ohms?

Yes

- Go To 4

No

- Repair the excessive resistance in the (N38) VVA Solenoid 4 Signal circuit.
- Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test.

4. CHECK FOR EXCESSIVE RESISTANCE IN THE (N39) VVA SOLENOID 4 RETURN CIRCUIT
1. Measure the resistance of the (N39) VVA Solenoid 4 Return circuit between the VVA Solenoid 4 harness connector and the PCM C2 harness connector.

Is the resistance below 5.0 Ohms?

Yes

- Go To 5

No

- Repair the excessive resistance in the (N39) VVA Solenoid 4 Return circuit.
- Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test.

5. POWERTRAIN CONTROL MODULE (PCM)
1. Using the wiring diagram/schematic as a guide, inspect the wiring and connectors between the Solenoid and the Powertrain Control Module (PCM).
2. Look for any chafed, pierced, pinched or partially broken wires.
3. Look for broken, bent, pushed out or corroded terminals. Verify that there is good pin to terminal contact in the Solenoid and the Powertrain Control Module harness connectors.
4. Perform any Technical Service Bulletins that may apply.

Were there any problems found?

Yes

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

No

- Replace and program the Powertrain Control Module. .
- Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test.