Page 1057 of 4331

CVT
N
O P
DTC P0840 TRANSMISSION FLUID
PRESSURE SENSOR A CIRCUIT
(SEC PRESSURE SENSOR)
Description INFOID:0000000004667002
• 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-III Reference Val ue in Data Monitor Mode INFOID:0000000004667003
Remarks: Specification data are reference values.
On Board Diagnosis Logic INFOID:0000000004667004
• This is an OBD-II self-diagnostic item.
• Diagnostic trouble code “P0840 TR PRS SENS/A CIRC” with CONSULT-III is detected when TCM detects
an improper voltage drop when it receives the sensor signal.
Possible Cause INFOID:0000000004667005
• Transmission fluid pressure sensor A (Secondary pressure sensor)
• Harness or connectors (Switch circuit is open or shorted.)
DTC Confirmation Procedure INFOID:0000000004667006
NOTE:
If “DTC Confirmation Procedure” has been previously performed, alw ays 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-III
1. Turn ignition switch ON and select “DATA MO NITOR” mode for “TRANSMISSION” with CONSULT-III.
2. Make sure that output voltage of line te mperature 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 (c ool down the fluid)
3. Start engine and wait for at least 5 consecutive seconds.
4. If DTC is detected, go to CVT-115, " Diagnosis Procedure " .
WITH GST
Follow the procedure “WITH CONSULT-III”. Item name Condition Display value (Approx.)
SEC HYDR SEN “N” position idle 1.0 V
SEC PRESS 0.8 MPa
Page 1058 of 4331
TCM Terminal and Reference Value " .
Page 1059 of 4331
![NISSAN LATIO 2009 Service Repair Manual DTC P0840 TRANSMISSION FLUID PR
ESSURE SENSOR A CIRCUIT (SEC
PRESSURE SENSOR)
CVT-115
< SERVICE INFORMATION >
[RE0F08A] D
E
F
G H
I
J
K L
M A
B CVT
N
O P
Diagnosis Procedure
INFOID:00000000046670081. NISSAN LATIO 2009 Service Repair Manual DTC P0840 TRANSMISSION FLUID PR
ESSURE SENSOR A CIRCUIT (SEC
PRESSURE SENSOR)
CVT-115
< SERVICE INFORMATION >
[RE0F08A] D
E
F
G H
I
J
K L
M A
B CVT
N
O P
Diagnosis Procedure
INFOID:00000000046670081.](/manual-img/5/57359/w960_57359-1058.png)
DTC P0840 TRANSMISSION FLUID PR
ESSURE SENSOR A CIRCUIT (SEC
PRESSURE SENSOR)
CVT-115
< SERVICE INFORMATION >
[RE0F08A] D
E
F
G H
I
J
K L
M A
B CVT
N
O P
Diagnosis Procedure
INFOID:00000000046670081.
CHECK INPUT SIGNAL
With CONSULT-III
1. Start engine.
2. Select “ECU INPUT SIGNALS” in “DATA MONITO R” mode for “TRANSMISSION” with CONSULT-III.
3. Start vehicle and read out the value of “SEC HYDR SEN”.
Without CONSULT-III
1. Start engine.
2. Check voltage between TCM connector terminal and ground.
OK or NG OK >> GO TO 5.
NG >> GO TO 2. 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 UNI T HARNESS CONNECTOR (SENSOR POWER ANDSENSOR 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 Item name Condition Display value (Approx.)
SEC HYDR SEN “N” position idle 1.0 V Name Connector Terminal Condition
Voltage
(Approx.)
Transmission
fluid pressure
sensor A
(Secondary
pressure sen-
sor) E32 37 - Ground “N” position idle 1.0 V SCIA4508E
Item Connector Terminal
Data (Ap-
prox.)
TCM connector E32 46 - 42 5.0 V SCIA2367E
Item Connector Terminal Continuity
TCM E32 42 Yes
CVT unit harness connector F46 19
TCM E32 46 Yes
CVT unit harness connector F46 20 SCIA4681E
Page 1060 of 4331
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 TRANSMISSI ON FLUID PRESSURE SENSOR A (SECOND-OK >> GO TO 5.
NG >> Repair open circuit or short to ground or short to power in harness or connectors. DTC Confirmation Procedure " .
OK or NG OK >>
INSPECTION END
NG >> GO TO 6. TCM Terminal and Reference Value " .
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-182, " Removal and Installation " .
NG >> Repair or replace damaged parts. Item Connector Terminal Continuity
TCM E32 37 Yes
CVT unit harness connector F46 23
Page 1061 of 4331

CVT
N
O P
DTC P0841 PRESSURE SENSOR FUNCTION
Description INFOID:0000000004667009
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 pr essure of the primary pulley and the secondary pul-
ley and changes the groove width of the pulley to control the gear ratio.
CONSULT-III Reference Val ue in Data Monitor Mode INFOID:0000000004667010
Remarks: Specification data are reference values.
On Board Diagnosis Logic INFOID:0000000004667011
• This is not an OBD-II self-diagnostic item.
• Diagnostic trouble code “P0841 PRESS SEN/FNCTN” wit h CONSULT-III is detected when correlation
between the values of the secondary pressure sensor and the primary pressure sensor is out of specifica-
tion.
Possible Cause INFOID:0000000004667012
• 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 Procedure INFOID:0000000004667013
CAUTION:
Always drive vehicle at a safe speed.
NOTE:
If “DTC Confirmation Procedure” has been previously performed, alw ays 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-III
1. Turn ignition switch ON and select “DATA MO NITOR” mode for “TRANSMISSION” with CONSULT-III.
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-117, " Diagnosis Procedure " .
Diagnosis Procedure INFOID:0000000004667014CONSULT-III Function (TRANSMISSION) " .
Is any malfunction of the “ U1000 CAN COMM CIRCUIT ” indicated?
YES >> Check CAN communication line. Refer to
CVT-60 .
NO >> GO TO 2.
Page 1062 of 4331

OK >> GO TO 6.
NG >> GO TO 3. Inspections before Trouble Diagnosis " .
OK or NG OK >> GO TO 4.
NG >> Repair or replace damaged parts. Refer to CVT-40, " Inspections before Trouble Diagnosis " .
4. CHECK TRANSMISSION FLUID PRESSURE SENS OR A (SECONDARY PRESSURE SENSOR) SYS- ,
CVT-119 .
OK or NG OK >> GO TO 5.
NG >> Repair or replace damaged parts. Component Inspec-
tion " .
• Pressure control solenoid valve B (Secondary pressure solenoid valve). Refer to CVT-111, " Component
Inspection " .
• Step motor. Refer to CVT-144, " Component Inspection " .
OK or NG6 OK >> GO TO 6.
NG >> Repair or replace damaged parts. DTC Confirmation Procedure " .
OK or NG OK >>
INSPECTION END
NG >> Replace TCM or transaxle assembly. Refer to CVT-182, " Removal and Installation " .
Item name Condition Display value (Approx.)
PRI HYDR SEN “N” position idle 0.7 V
SEC HYDR SEN 1.0 V Name Connector Terminal Condition
Voltage
(Approx.)
Transmission fluid
pressure sensor B
(Primary pres-
sure sensor) E3241 - Ground
“N” position idle 0.7 V
Transmission fluid
pressure sensor A
(Secondary pres-
sure sensor) 37 - Ground 1.0 V
Page 1063 of 4331

CVT
N
O P
DTC P0845 TRANSMISSION FLUID PR
ESSURE SENSOR B CIRCUIT (PRI
PRESSURE SENSOR)
Description INFOID:0000000004667015
• The transmission fluid pressure sensor B (primary pre ssure sensor) is included in the control valve assem-
bly.
• The transmission fluid pressure sensor B (primary pr essure sensor) detects primary pressure of CVT and
sends TCM the signal.
CONSULT-III Reference Val ue in Data Monitor Mode INFOID:0000000004667016
Remarks: Specification data are reference values.
On Board Diagnosis Logic INFOID:0000000004667017
• This is an OBD-II self-diagnostic item.
• Diagnostic trouble code “P0845 TR PRS SENS/B CIRC” wi th CONSULT-III is detected under the following
conditions.
- When TCM detects an improper voltage drop when it receives the sensor signal.
- When TCM compares target value with monitor value and detects an irregularity.
Possible Cause INFOID:0000000004667018
• Transmission fluid pressure sensor B (Primary pressure sensor)
• Harness or connectors (Sensor circuit is open or shorted.)
DTC Confirmation Procedure INFOID:0000000004667019
NOTE:
If “DTC Confirmation Procedure” has been previously performed, alw ays 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-III
1. Turn ignition switch ON and select “DATA MO NITOR” mode for “TRANSMISSION” with CONSULT-III.
2. Make sure that output voltage of line te mperature 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 (c ool down the fluid)
3. Start engine and wait for at least 5 consecutive seconds.
4. If DTC is detected, go to CVT-121, " Diagnosis Procedure " .
WITH GST
Follow the procedure “WITH CONSULT-III”. Item name Condition Display value (Approx.)
PRI HYDR SEN “N” position idle 0.7 V
Page 1064 of 4331
TCM Terminal and Reference Value " .