Nissan Altima 2007-2012 Service Manual: P0841 pressure sensor function
Description
Using the engine load (throttle position), the primary pulley revolution speed, and the secondary pulley revolution speed as input signal, 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: If “DTC CONFIRMATION PROCEDURE” has been previously performed, always turn ignition switch OFF.
Then wait at least 10 seconds before performing the next test.
1.CHECK DTC DETECTION
1. Turn ignition switch ON.
2. Select “DATA MONITOR”.
3. Start engine and maintain the following conditions for at least 12 consecutive seconds.
Is “P0841 PRESS SEN/FNCTN” detected? YES >> Go to TM-163, "Diagnosis Procedure".
NO >> Check intermittent incident. Refer to GI-42, "Intermittent Incident".
Diagnosis Procedure
1.CHECK LINE PRESSURE
Perform line pressure test. Refer to TM-247, "Inspection and Judgment".
Is the inspection result normal? YES >> .GO TO 2.
NO >> Repair or replace damaged parts. Refer to TM-247, "Inspection and Judgment".
2.CHECK TRANSMISSION FLUID PRESSURE SENSOR A (SECONDARY PRESSURE SENSOR) SYSTEM
Check transmission fluid pressure sensor A (secondary pressure sensor) system. Refer to TM-160, "Description".
Is the inspection result normal? YES >> GO TO 3.
NO >> Repair or replace damaged parts.
3.CHECK TRANSMISSION FLUID PRESSURE SENSOR B (PRIMARY PRESSURE SENSOR) SYSTEM
Check transmission fluid pressure sensor B (primary pressure sensor) system. Refer to TM-166, "Description".
Is the inspection result normal? YES >> GO TO 4.
NO >> Repair or replace damaged parts.
4.CHECK PRESSURE CONTROL SOLENOID VALVE A (LINE PRESSURE SOLENOID VALVE)
1. Turn ignition switch OFF.
2. Disconnect CVT unit harness connector.
3. Check pressure control solenoid valve A (line pressure solenoid valve). Refer to TM-164, "Component Inspection [Pressure Control Solenoid Valve A (Line Pressure Solenoid Valve)]".
Is the inspection result normal? YES >> GO TO 5.
NO >> Repair or replace damaged parts.
5.CHECK PRESSURE CONTROL SOLENOID VALVE B (SECONDARY PRESSURE SOLENOID VALVE)
Check pressure control solenoid valve B (secondary pressure solenoid valve). Refer to TM-164, "Component Inspection [Pressure Control Solenoid Valve B (Secondary Pressure Solenoid Valve)]".
Is the inspection result normal? YES >> GO TO 6.
NO >> Repair or replace damaged parts.
6.CHECK STEP MOTOR SYSTEM
Check step motor system. Refer to TM-184, "Description".
Is the inspection result normal? YES >> GO TO 7.
NO >> Repair or replace damaged parts.
7.DETECT MALFUNCTIONING ITEMS
Check TCM connector pin terminals for damage or loose connection with harness connector.
Is the inspection result normal? YES >> Replace TCM. Refer to TM-254, "Exploded View".
NO >> Repair or replace damaged parts.
Component Inspection [Pressure Control Solenoid Valve A (Line Pressure Solenoid Valve)
1.CHECK PRESSURE CONTROL SOLENOID VALVE A (LINE PRESSURE SOLENOID VALVE)
Check resistance between CVT unit terminal 2 and ground.
Is the inspection result normal? YES >> INSPECTION END
NO >> Replace transaxle assembly. Refer to TM-259, "Exploded View".
Component Inspection [Pressure Control Solenoid Valve B (Secondary Pressure Solenoid Valve)
1.CHECK PRESSURE CONTROL SOLENOID VALVE B (SECONDARY PRESSURE SOLENOID VALVE)
Check resistance between CVT unit terminal 3 and ground.
Is the inspection result normal? YES >> INSPECTION END
NO >> Replace transaxle assembly. Refer to TM-259, "Exploded View".
P0840 transmission fluid pressure
sensor A (sec pressure sensor)
Description
The transmission fluid pressure sensor A (secondary pressure sensor) detects
secondary pressure of CVT
and sends TCM the signal.
DTC Logic
DTC DETECTION LOGIC
DTC CONFIRMATION PRO ...
P0845 transmission fluid pressure
sensor B (pri pressure sensor)
Description
The transmission fluid pressure sensor B (primary pressure sensor) detects
primary pressure of CVT and
sends TCM the signal.
DTC Logic
DTC DETECTION LOGIC
DTC CONFIRMATION PROCE ...
Other materials:
Front power window switch
Reference Value
TERMINAL LAYOUT
PHYSICAL VALUES
POWER WINDOW AND DOOR LOCK/UNLOCK SWITCH RH
Wiring Diagram
Fail Safe
FAIL-SAFE CONTROL
Switches to fail-safe control when malfunction is detected in encoder signal
that detects up/down speed and
direction of door glass. Swi ...
Diagnosis sensor unit
Removal and Installation
REMOVAL
1. Diagnosis sensor unit harness connector
2. Diagnosis sensor unit shield
3. Diagnosis sensor unit
A. Diagnosis sensor unit bolts
CAUTION:
• Before servicing, turn ignition switch OFF, disconnect both battery terminals
and wait at least three
minutes ...
Mixture ratio self-learning value
clear
Description
This describes how to erase the mixture ratio self-learning value. For the
actual procedure, follow the instructions
in “Diagnosis Procedure”.
Special Repair Requirement
1.START
1. Start engine and warm it up to normal operating temperature.
2. Select “SELF-LEARNING CO ...