Nissan Maxima Service and Repair Manual: P0841 transmission fluid pressure SEN/SW A

Description

Using the engine load (throttle position), the primary pulley revolution speed, and the secondary pulley revolution speed as input signals, TCM changes the operating pressure of the primary pulley and the secondary pulley and changes the groove width of the pulley to control the gear ratio.

DTC Logic

DTC DETECTION LOGIC

DTC CONFIRMATION PROCEDURE

CAUTION: Always drive vehicle at a safe speed.

NOTE: Immediately after performing any "DTC CONFIRMATION PROCEDURE", always turn ignition switch OFF.

Then wait at least 10 seconds before performing the next test.

1.CHECK DTC DETECTION

With CONSULT

  1.  Turn ignition switch ON.
  2.  Select "Data Monitor" in "TRANSMISSION".
  3.  Start engine and maintain the following conditions for at least 12 consecutive seconds.

VEHICLE SPEED : 40 km/h (25 MPH) or more

RANGE : "D" position

Diagnosis Procedure

1.CHECK LINE PRESSURE

Perform line pressure test. Refer to TM-162, "Inspection and Judgment".

2.CHECK SECONDARY PRESSURE SENSOR SYSTEM

Check secondary pressure sensor system. Refer to TM-85, "Description".

3.CHECK PRIMARY PRESSURE SENSOR SYSTEM

Check primary pressure sensor system. Refer to TM-90, "Description".

4.CHECK LINE PRESSURE SOLENOID VALVE

  1.  Turn ignition switch OFF.
  2.  Disconnect CVT unit connector.
  3.  Check line pressure solenoid valve. Refer to TM-89, "Component Inspection (Line Pressure Solenoid Valve)".

5.CHECK SECONDARY PRESSURE SOLENOID VALVE

Check secondary pressure solenoid valve. Refer to TM-89, "Component Inspection (Secondary Pressure Solenoid Valve)".

6.CHECK STEP MOTOR SYSTEM

Check step motor system. Refer to TM-109, "Description".

7.DETECT MALFUNCTIONING ITEMS

Check TCM connector pin terminals for damage or loose connection with harness connector.

Component Inspection (Line Pressure Solenoid Valve)

1.CHECK LINE PRESSURE SOLENOID VALVE

Check resistance between CVT unit connector terminal and ground.

Component Inspection (Secondary Pressure Solenoid Valve)

1.CHECK SECONDARY PRESSURE SOLENOID VALVE

Check resistance between CVT unit connector terminal and ground.

    P0840 transmission fluid pressure SEN/SW A

    P0845 transmission fluid pressure SEN/SW B