Nissan Altima 2007-2012 Service Manual: P0868 secondary pressure down

Description

The pressure control solenoid valve B (secondary pressure solenoid valve) regulates the secondary pressure to suit the driving condition in response to a signal sent from the TCM.

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. Make sure that output voltage of CVT fluid temperature sensor is within the range below.

ATF TEMP SEN : 1.0 – 2.0 V

If out of range, drive the vehicle to decrease the voltage (warm up the fluid) or stop engine to increase the voltage (cool down the fluid)

4. Start engine and maintain the following conditions for at least 10 consecutive seconds.

Is “P0868 SEC/PRESS DOWN” detected? YES >> Go to TM-169, "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 PRESSURE CONTROL SOLENOID VALVE B (SECONDARY PRESSURE SOLENOID VALVE)

1. Turn ignition switch OFF.

2. Disconnect CVT unit harness connector.

3. Check pressure control solenoid valve B (secondary pressure solenoid valve). Refer to TM-170, "Component Inspection [Pressure Control Solenoid Valve B (Secondary Pressure Solenoid Valve)]".

Is the inspection result normal? YES >> GO TO 3.

NO >> Repair or replace damaged parts.

3.CHECK PRESSURE CONTROL SOLENOID VALVE A (LINE PRESSURE SOLENOID VALVE)

Check pressure control solenoid valve A (line pressure solenoid valve). Refer to TM-170, "Component Inspection [Pressure Control Solenoid Valve A (Line Pressure Solenoid Valve)]".

Is the inspection result normal? YES >> GO TO 4.

NO >> Repair or replace damaged parts.

4.CHECK TRANSMISSION FLUID PRESSURE SENSOR A (SECONDARY PRESSURE SENSOR) SYSTEM

Check transmission fluid pressure sensor A (secondary pressure sensor) system. Refer to TM-160, "DTC Logic".

Is the inspection result normal? YES >> GO TO 5.

NO >> Repair or replace damaged parts.

5.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".

    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 ...

    P1701 transmission control module (power supply)
    Description When the power supply to the TCM is cut OFF, for example because the battery is removed, and the self-diagnosis memory function stops, malfunction is detected. NOTE: Since “P170 ...

    Other materials:

    Compass display (if so equipped)
    This unit measures terrestrial magnetism and indicates the direction of the vehicle’s heading. With the ignition switch placed in the ON position, press the button as described in the chart below to activate various features of the automatic anti-glare rearview mirror. For information ...

    P2101 electric throttle control function
    Description Electric throttle control actuator consists of throttle control motor, throttle position sensor, etc. The throttle control motor is operated by the ECM and it opens and closes the throttle valve. The current opening angle of the throttle valve is detected by the throttle po ...

    Memory function does not operate
    Diagnosis Procedure SYMPTOM: Memory function does not operate. The setting is not maintained (it returns to the initial condition). Inspection procedure 1.CHECK OPERATION 1. Set temperature control dial to 32°C (90°F). 2. Press OFF switch. 3. Press ignition switch OFF. 4. Press ig ...