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CVT-128
DTC P0778 PRESSURE CONTROL SOLENOID B ELECTRICAL (SEC PRES-
SURE SOLENOID VALVE)
Revision: June 20062007 Versa
6. CHECK TCM
1. Check TCM input/output signals. Refer to CVT-54, "
TCM Input/Output Signal Reference Values" .
2. If NG, re-check TCM pin terminals for damage or loose connection with harness connector.
OK or NG
OK >>INSPECTION END
NG >> 1. Repair or replace damaged parts.
2. Replace the transaxle assembly. Refer to CVT-207, "
Removal and Installation" .
Component InspectionUCS0061E
PRESSURE CONTROL SOLENOID VALVE B (SECONDARY PRESSURE SOLENOID VALVE)
1. Turn ignition switch OFF.
2. Disconnect CVT unit harness connector.
3. Check resistance between CVT unit harness connector terminal
and ground.
4. If NG, replace the transaxle assembly. Refer to CVT-207,
"Removal and Installation" .
Solenoid Valve Connector TerminalResistance
(Approx.)
Pressure control sole-
noid valve B (Secondary
pressure solenoid valve) F46 3 - Ground 2.5 - 5.0 Ω
SCIA4688E
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DTC P0840 TRANSMISSION FLUID PRESSURE SENSOR A CIRCUIT (SEC
PRESSURE SENSOR)
CVT-129
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Revision: June 20062007 Versa
DTC P0840 TRANSMISSION FLUID PRESSURE SENSOR A CIRCUIT (SEC
PRESSURE SENSOR)
PFP:31936
DescriptionUCS0061N
The transmission fluid pressure sensor A (secondary pressure sensor) is included in the control valve
assembly.
The transmission fluid pressure sensor A (secondary pressure sensor) detects secondary pressure of
CVT and sends TCM the signal.
CONSULT-II Reference ValueUCS0061O
Remarks: Specification data are reference values.
On Board Diagnosis LogicUCS0061P
This is an OBD-II self-diagnostic item.
Diagnostic trouble code “P0840 TR PRS SENS/A CIRC” with CONSULT-II is detected when TCM detects
an improper voltage drop when it receives the sensor signal.
Possible CauseUCS0061Q
Transmission fluid pressure sensor A (Secondary pressure sensor)
Harness or connectors
(Switch circuit is open or shorted.)
DTC Confirmation ProcedureUCS0061R
NOTE:
If “DTC Confirmation Procedure” has been previously performed, always turn ignition switch OFF and
wait at least 10 seconds before performing the next test.
After the repair, perform the following procedure to confirm the malfunction is eliminated.
WITH CONSULT-II
1. Turn ignition switch ON and select “DATA MONITOR” mode for
“TRANSMISSION” with CONSULT-II.
2. Make sure that output voltage of line 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)
3. Start engine and wait for at least 5 consecutive seconds.
4. If DTC is detected, go to CVT-131, "
Diagnostic Procedure" .
WITH GST
Follow the procedure “WITH CONSULT-II”.
Item name Condition Display value (Approx.)
SEC HYDR SEN
“N” position idle1.0 V
SEC PRESS0.8 MPa
BCIA0031E
Page 1027 of 2896
CVT-130
DTC P0840 TRANSMISSION FLUID PRESSURE SENSOR A CIRCUIT (SEC
PRESSURE SENSOR)
Revision: June 20062007 Versa
Wiring Diagram — CVT — SECPSUCS0061S
BCWA0677E
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DTC P0840 TRANSMISSION FLUID PRESSURE SENSOR A CIRCUIT (SEC
PRESSURE SENSOR)
CVT-131
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Revision: June 20062007 Versa
TCM terminal data are reference values, measured between each terminal and ground.
Diagnostic ProcedureUCS0061T
1. CHECK INPUT SIGNAL
With CONSULT-II
1. Start engine.
2. Select “ECU INPUT SIGNALS” in “DATA MONITOR” mode for
“TRANSMISSION” with CONSULT-II.
3. Start vehicle and read out the value of “SEC HYDR SEN”.
Without CONSULT-II
1. Start engine.
2. Check voltage between TCM connector terminal and ground.
OK or NG
OK >> GO TO 5.
NG >> GO TO 2.
Terminal Wire color Item Condition Data (Approx.)
37 LTransmission fluid
pressure sensor A
(Secondary pres-
sure sensor)and “N” position idle 1.0 V
42 LG Sensor ground Always 0 V
46 O Sensor power—5.0 V
— 0 V
Item name Condition Display value (Approx.)
SEC HYDR SEN “N” position idle 1.0 V
SCIA2279E
Name Connector Terminal ConditionVoltage
(Approx.)
Transmission
fluid pres-
sure sensor A
(Secondary
pressure sen-
sor)E32 37 - Ground “N” position idle 1.0 V
SCIA4508E
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CVT-132
DTC P0840 TRANSMISSION FLUID PRESSURE SENSOR A CIRCUIT (SEC
PRESSURE SENSOR)
Revision: June 20062007 Versa
2. CHECK SENSOR POWER AND SENSOR GROUND
1. Turn ignition switch ON. (Do not start engine)
2. Check voltage between TCM connector terminals.
OK or NG
OK >> GO TO 4.
NG >> GO TO 3.
3. CHECK HARNESS BETWEEN TCM AND CVT UNIT HARNESS CONNECTOR (SENSOR POWER
AND SENSOR GROUND)
1. Turn ignition switch OFF.
2. Disconnect TCM connector and CVT unit harness connector.
3. Check continuity between TCM connector terminals and CVT
unit harness connector terminals.
4. If OK, check harness for short to ground and short to power.
5. Reinstall any part removed.
OK or NG
OK >> Replace TCM. Refer to CVT-9, "Service After Replacing TCM and Transaxle Assembly" .
NG >> Repair open circuit or short to ground or short to power in harness or connectors.
4. CHECK HARNESS BETWEEN TCM AND TRANSMISSION FLUID PRESSURE SENSOR A (SECOND-
ARY PRESSURE SENSOR)
1. Turn ignition switch OFF.
2. Disconnect TCM connector and CVT unit harness connector.
3. Check continuity between TCM connector terminal and CVT unit
harness connector terminal.
4. If OK, check harness for short to ground and short to power.
5. Reinstall any part removed.
OK or NG
OK >> GO TO 5.
NG >> Repair open circuit or short to ground or short to power
in harness or connectors.
Item Connector TerminalData
(Approx.)
TCM connector E32 46 - 42 5.0 V
SCIA2367E
Item Connector Terminal Continuity
TCM E32 42
Ye s
CVT unit harness connector F46 19
TCM E32 46
Ye s
CVT unit harness connector F46 20
SCIA4681E
Item Connector Terminal Continuity
TCM E32 37
Ye s
CVT unit harness connector F46 23
SCIA4690E
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DTC P0840 TRANSMISSION FLUID PRESSURE SENSOR A CIRCUIT (SEC
PRESSURE SENSOR)
CVT-133
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Revision: June 20062007 Versa
5. CHECK DTC
Perform CVT-129, "
DTC Confirmation Procedure" .
OK or NG
OK >>INSPECTION END
NG >> GO TO 6.
6. CHECK TCM
1. Check TCM input/output signals. Refer to CVT-54, "
TCM Input/Output Signal Reference Values" .
2. If NG, re-check TCM pin terminals for damage or loose connection with harness connector.
OK or NG
OK >> Replace the transaxle assembly. Refer to CVT-207, "Removal and Installation" .
NG >> Repair or replace damaged parts.
Page 1031 of 2896

CVT-134
DTC P0841 PRESSURE SENSOR FUNCTION
Revision: June 20062007 Versa
DTC P0841 PRESSURE SENSOR FUNCTIONPFP:31936
DescriptionUCS0061U
Using the engine load (throttle position), the primary pulley revolution speed, and the secondary pulley revolu-
tion speed as input signal, TCM changes the operating pressure of the primary pulley and the secondary pul-
ley and changes the groove width of the pulley to control the gear ratio.
CONSULT-II Reference ValueUCS0061V
Remarks: Specification data are reference values.
On Board Diagnosis LogicUCS0061W
This is not an OBD-II self-diagnostic item.
Diagnostic trouble code “P0841 PRESS SEN/FNCTN” with CONSULT-II is detected when correlation
between the values of the secondary pressure sensor and the primary pressure sensor is out of specifica-
tion.
Possible CauseUCS0061X
Transmission fluid pressure sensor A (Secondary pressure sensor)
Transmission fluid pressure sensor B (Primary pressure sensor)
Harness or connectors
(Sensor circuit is open or shorted.)
DTC Confirmation ProcedureUCS0061Y
CAUTION:
Always drive vehicle at a safe speed.
NOTE:
If “DTC Confirmation Procedure” has been previously performed, always turn ignition switch OFF and
wait at least 10 seconds before performing the next test.
After the repair, perform the following procedure to confirm the malfunction is eliminated.
WITH CONSULT-II
1. Turn ignition switch ON and select “DATA MONITOR” mode for
“TRANSMISSION” with CONSULT-II.
2. Start engine and maintain the following conditions for at least 12
consecutive seconds.
VEHICLE SPEED: 40 km/h (25 MPH) More than
RANGE: “D” position
3. If DTC is detected, go to CVT-135, "
Diagnostic Procedure" .
Item name Condition Display value (Approx.)
PRI HYDR SEN
“N” position idle0.7 V
SEC HYDR SEN1.0 V
BCIA0031E
Page 1032 of 2896

DTC P0841 PRESSURE SENSOR FUNCTION
CVT-135
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Diagnostic ProcedureUCS0061Z
1. CHECK CAN COMMUNICATION LINE
Perform the self-diagnosis. Refer to CVT-60, "
SELF-DIAGNOSTIC RESULT MODE" .
Is any malfunction of the
“U1000 CAN COMM CIRCUIT” indicated?
YES >> Check CAN communication line. Refer to CVT-68, "DTC U1000 CAN COMMUNICATION LINE" .
NO >> GO TO 2.
2. CHECK INPUT SIGNALS
With CONSULT-II
1. Start engine.
2. Select “ECU INPUT SIGNALS” in “DATA MONITOR” mode for
“TRANSMISSION” with CONSULT-II.
3. Start vehicle and read out the value of “SEC HYDR SEN” and
“PRI HYDR SEN”.
Without CONSULT-II
1. Start engine.
2. Check voltage between TCM connector terminals and ground.
OK or NG
OK >> GO TO 6.
NG >> GO TO 3.
3. CHECK LINE PRESSURE
Perform line pressure test. Refer to CVT-45, "
LINE PRESSURE TEST" .
OK or NG
OK >> GO TO 4.
NG >> Repair or replace damaged parts. Refer to CVT-46, "
Judgement of Line Pressure Test" .
4. CHECK TRANSMISSION FLUID PRESSURE SENSOR A (SECONDARY PRESSURE SENSOR) SYS-
TEM AND TRANSMISSION FLUID PRESSURE SENSOR B (PRIMARY PRESSURE SENSOR) SYSTEM
Check transmission fluid pressure sensor A (secondary pressure sensor) system and transmission fluid pres-
sure sensor B (primary pressure sensor) system. Refer to CVT-129, "
DTC P0840 TRANSMISSION FLUID
Item name Condition Display value (Approx.)
PRI HYDR SEN
“N” position idle0.7 V
SEC HYDR SEN 1.0 V
SCIA2277E
Name Connector Terminal ConditionVoltage
(Approx.)
Transmission fluid
pressure sensor B
(Primary pres-
sure sensor)
E3241 - Ground
“N” position idle0.7 V
Transmission fluid
pressure sensor A
(Secondary pres-
sure sensor)37 - Ground 1.0 V
SCIA6879E