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:
Brake precautions
Vacuum assisted brakes
The brake booster aids braking by using engine
vacuum. If the engine stops, you can stop the
vehicle by depressing the brake pedal. However,
greater foot pressure on the brake pedal will be
required to stop the vehicle and stopping distance
will be longer.
Using the b ...
Precaution
Precaution for Supplemental Restraint System
(SRS) "AIR BAG" and "SEAT BELT PRE-TENSIONER"
The Supplemental Restraint System such as “AIR BAG” and “SEAT BELT
PRE-TENSIONER”, used along
with a front seat belt, helps to reduce the risk or severity of injury to the
dr ...
Basic inspection
DIAGNOSIS AND REPAIR WORKFLOW
Work Flow
DETAILED FLOW
1.OBTAIN INFORMATION ABOUT SYMPTOM
Interview the customer to obtain as much information as possible about the
conditions and environment under
which the malfunction occurred.
>> GO TO 2
2.CHECK SYMPTOM
• Check the symptom bas ...