Nissan Maxima Service and Repair Manual: P1078, P1084 EVT control position sensor

Description

Exhaust valve timing control position sensor detects the concave groove of the exhaust camshaft rear end.

This sensor signal is used for sensing a position of the exhaust camshaft.

This sensor uses a Hall IC.

Based on the position of the exhaust camshaft, ECM controls exhaust valve timing control magnet retarder to optimize the shut/ open timing of exhaust valve for the driving condition.

DTC Logic

DTC DETECTION LOGIC

NOTE: If DTC P1078 or P1084 is displayed with DTC P0643, first perform the trouble diagnosis for DTC P0643.

Refer to EC-394, "DTC Logic".

DTC CONFIRMATION PROCEDURE

1.PRECONDITIONING

If DTC Confirmation Procedure has been previously conducted, always perform the following procedure before conducting the next test.

1. Turn ignition switch OFF and wait at least 10 seconds.
2. Turn ignition switch ON.
3. Turn ignition switch OFF and wait at least 10 seconds.

2.PERFORM DTC CONFIRMATION PROCEDURE

1. Start engine and let it idle for 10 seconds.
2. Check 1st trip DTC.

Diagnosis Procedure

1.CHECK GROUND CONNECTION

1. Turn ignition switch OFF.
2. Check ground connection E9.

2.CHECK EXHAUST VALVE TIMING (EVT) CONTROL POSITION SENSOR POWER SUPPLY CIRCUIT-I

1. Disconnect EVT control position sensor harness connector.
2. Turn ignition switch ON.
3. Check the voltage between EVT control position sensor harness connector and ground.

3.CHECK EVT CONTROL POSITION SENSOR GROUND CIRCUIT FOR OPEN AND SHORT

1. Turn ignition switch OFF.
2. Disconnect ECM harness connector.
3. Check the continuity between EVT control position sensor harness connector and ECM harness connector.
4. Also check harness for short to ground and short to power.

4.CHECK EVT CONTROL POSITION SENSOR INPUT SIGNAL CIRCUIT FOR OPEN AND SHORT

1. Check the continuity between EVT control position sensor harness connector and ECM harness connector.
2. Also check harness for short to ground and short to power.

5.CHECK EVT CONTROL POSITION SENSOR

6.CHECK CAMSHAFT (EXH)

Check the following.

• Accumulation of debris to the signal plate of camshaft rear end
• Chipping signal plate of camshaft rear end

7.CHECK INTERMITTENT INCIDENT

Component Inspection

1.EXHAUST VALVE TIMING CONTROL POSITION SENSOR-I

1. Turn ignition switch OFF.
2. Disconnect exhaust valve timing control position sensor harness connector.
3. Loosen the fixing bolt of the sensor.
4. Remove the sensor.
5. Visually check the sensor for chipping.

2.EXHAUST VALVE TIMING CONTROL POSITION SENSOR-II

Check resistance exhaust valve timing control position sensor terminals as shown below.