NISSAN LATIO 2007 Service Repair Manual

AT-128
DTC P0734 A/T 4TH GEAR FUNCTION
Revision: June 20062007 Versa
DTC P0734 A/T 4TH GEAR FUNCTIONPFP:31940
DescriptionUCS005ON

This malfunction will not be detected while the OD OFF indicator lamp is indicating another self-diagnosis
malfunction.

This malfunction is detected when the A/T does not shift into fourth gear position or the torque converter
clutch does not lock up as instructed by the TCM. This is not caused by electrical malfunction (circuits
open or shorted) but by mechanical malfunction such as control valve sticking, improper solenoid valve
operation, malfunctioning oil pump or torque converter clutch, etc.
CONSULT-II Reference ValueUCS005OO
Remarks: Specification data are reference values.
On Board Diagnosis LogicUCS005OP

This is an OBD-II self-diagnostic item.

Diagnostic trouble code “P0734 A/T 4TH GR FNCTN” with CONSULT-II is detected when A/T cannot be
shifted to the 4th gear position even if electrical circuit is good.

This diagnosis monitors actual gear position by checking the torque converter slip ratio calculated by TCM
as follows:
Torque converter slip ratio = A x C/B
A: Output shaft revolution signal from revolution sensor
B: Engine speed signal from ECM
C: Gear ratio determined as gear position which TCM supposes
If the actual gear position is much lower than the position (4th) supposed by TCM, the slip ratio will be
much less than normal. In case the ratio does not reach the specified value, TCM judges this diagnosis
malfunction.
This malfunction will be caused when shift solenoid valve A is stuck open or shift solenoid valve B is stuck
closed.

Gear positions supposed by TCM are as follows.
In case of gear position with no malfunctions: 1, 2, 3 and 4 positions
In case of gear position with shift solenoid valve A stuck open: 2, 2, 3 and 3* positions
In case of gear position with shift solenoid valve B stuck closed: 1, 2, 2 and 1* positions to each gear
position above
*: “P0734 A/T 4TH GR FNCTN” is detected.
Possible CauseUCS005OQ

Shift solenoid valve A

Shift solenoid valve B

Line pressure solenoid valve

Each clutch

Hydraulic control circuit
Gear position 1 2 3 4
Shift solenoid valve A ON (Closed) OFF (Open) OFF (Open) ON (Closed)
Shift solenoid valve B ON (Closed) ON (Closed) OFF (Open) OFF (Open)
Item name Condition Display value (Approx.)
LINE PRES DTYSmall throttle opening (Low line pressure) ⇔ Large
throttle opening (High line pressure)0% ⇔ 94%

DTC P0734 A/T 4TH GEAR FUNCTION
AT-129
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Revision: June 20062007 Versa
DTC Confirmation ProcedureUCS005O R
CAUTION:

Always drive vehicle at a safe speed.

If performing this “DTC Confirmation Procedure” again, always turn ignition switch OFF and wait
at least 10 seconds before continuing.
After the repair, perform the following procedure to confirm the malfunction is eliminated.
WITH CONSULT-II
1. Start engine and select “DATA MONITOR” mode for “A/T” with
CONSULT-II.
2. Touch “START”.
3. Make sure that output voltage of A/T fluid temperature sensor is
within the range below.
FLUID TEMP SE: 0.4 - 1.5 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. Select “4TH GR FNCTN P0734” of “DTC WORK SUPPORT”
mode for “A/T” with CONSULT-II and touch “START”.
5. Accelerate vehicle to 55 to 65 km/h (34 to 40 MPH) under the following conditions and release the accel-
erator pedal completely.
THROTTLE POSI: Less than 5.5/8 (at all times during step 4)
SLCT LVR POSI: “D” position
–Make sure that “GEAR” shows “3” after releasing pedal.
6. Depress accelerator pedal steadily with 1.0/8 - 2.0/8 of “THROTTLE POSI” from a speed of 55 to 65 km/h
(34 to 40 MPH) until “TESTING” has turned to “STOP VEHICLE” or “COMPLETED”. (It will take approxi-
mately 3 seconds.)
If the check result NG appears on CONSULT-II screen, go to AT-130, "
Diagnostic Procedure" .
If “STOP VEHICLE” appears on CONSULT-II screen, go to following step.
–Make sure that “GEAR” shows “4” when depressing accelerator pedal with 1.0/8 - 2.0/8 of
“THROTTLE POSI”.
–If “TESTING” does not appear on CONSULT-II for a long time, select “SELF-DIAG RESULTS” for
“A/T”. In case a DTC other than “P0734 A/T 4TH GR FNCTN” is shown, refer to AT- 8 2 , "
Display
Items List" .
7. Stop vehicle.
8. Follow the instruction displayed. (Check for normal shifting referring to the table below.)
9. Make sure that “OK” is displayed. (If “NG” is displayed, refer to “Diagnostic Procedure”.)
Refer to AT- 1 3 0 , "
Diagnostic Procedure" .
Refer to AT- 6 7 , "
Vehicle Speed at Which Gear Shifting Occurs" .
WITH GST
Follow the procedure “WITH CONSULT-II”.
Vehicle condition Gear on actual transmission shift pattern when screen is changed to 1 → 2 → 3 → 4
No malfunction exists 1 → 2 → 3 → 4
Malfunction for “A/T 4TH GR FNCTN” exists.2 → 2 → 3 → 3
1 → 2 → 2 → 1
BCIA0031E

AT-130
DTC P0734 A/T 4TH GEAR FUNCTION
Revision: June 20062007 Versa
Diagnostic ProcedureUCS005OS
1. CHECK SHIFT-UP (D3 TO D4 )
During AT- 6 1 , "
Cruise Test — Part 1" .
Does A/T shift from D
3 to D4 at the specified speed?
YES >> GO TO 11.
NO >> GO TO 2.
2. CHECK LINE PRESSURE
Perform line pressure test. Refer to AT-56, "
LINE PRESSURE TEST" .
OK or NG
OK >> GO TO 3.
NG >> GO TO 7.
3. CHECK VALVE RESISTANCE
1. Remove control valve assembly. Refer to AT-242, "
Control Valve Assembly and Accumulators" .
–Shift solenoid valve A
–Shift solenoid valve B
2. Check resistance between terminal cord assembly harness con-
nector terminals and ground. Refer to AT-152, "
Wiring Diagram
— AT — SSV/A" and AT-157, "Wiring Diagram — AT — SSV/B"
.
OK or NG
OK >> GO TO 4.
NG >> Replace solenoid valve assembly.
SCIA7190E
Solenoid valve Connector Terminal Resistance (Approx.)
Shift solenoid valve A
F302 - Ground 20 - 30 Ω
Shift solenoid valve B 1 - Ground 5 - 20 Ω
SCIA3594E

DTC P0734 A/T 4TH GEAR FUNCTION
AT-131
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4. CHECK VALVE OPERATION
1. Remove control valve assembly. Refer to AT-242, "
Control Valve Assembly and Accumulators" .
–Shift solenoid valve A
–Shift solenoid valve B
2. Check solenoid valve by listening for its operating sound while
applying battery voltage to the terminals and ground. Refer to
AT-152, "
Wiring Diagram — AT — SSV/A" and AT - 1 5 7 , "Wiring
Diagram — AT — SSV/B" .
OK or NG
OK >> GO TO 5.
NG >> Replace solenoid valve assembly.
5. CHECK CONTROL VALVE
1. Disassemble control valve assembly. Refer to AT-293, "
Control Valve Assembly" .
2. Check to ensure that:
–Valve, sleeve and plug slide along valve bore under their own weight.
–Valve, sleeve and plug are free from burrs, dents and scratches.
–Control valve springs are free from damage, deformation and fatigue.
–Hydraulic line is free from obstacles.
OK or NG
OK >> GO TO 6.
NG >> Repair control valve.
6. CHECK SHIFT-UP (D3 TO D4 )
During AT-61, "
Cruise Test — Part 1" .
Does A/T shift from D
3 to D4 at the specified speed?
YES >> GO TO 11.
NO >> Check control valve again. Repair or replace control
valve assembly.
SCIA3595E
SCIA7190E

AT-132
DTC P0734 A/T 4TH GEAR FUNCTION
Revision: June 20062007 Versa
7. CHECK VALVE RESISTANCE
1. Remove control valve assembly. Refer to AT-242, "
Control Valve Assembly and Accumulators" .
–Line pressure solenoid valves
2. Check resistance between terminal cord assembly harness con-
nector terminal and ground. Refer to AT-146, "
Wiring Diagram
— AT — LPSV" .
OK or NG
OK >> GO TO 8.
NG >> Replace solenoid valve assembly.
8. CHECK VALVE OPERATION
1. Remove control valve assembly. Refer to AT-242, "
Control Valve Assembly and Accumulators" .
–Line pressure solenoid valves
2. Check solenoid valve by listening for its operating sound while
applying battery voltage to the terminal and ground. Refer to AT-
146, "Wiring Diagram — AT — LPSV" .
OK or NG
OK >> GO TO 9.
NG >> Replace solenoid valve assembly.
9. CHECK CONTROL VALVE
1. Disassemble control valve assembly. Refer to AT-293, "
Control Valve Assembly" .
2. Check line pressure circuit valves for sticking.
–Pilot valve
–Shift solenoid valve A
–Shift solenoid valve B
OK or NG
OK >> GO TO 10.
NG >> Repair control valve.
10. CHECK SHIFT-UP (D3 TO D4 )
During AT- 6 1 , "
Cruise Test — Part 1" .
Does A/T shift from D
3 to D4 at the specified speed?
YES >> GO TO 11.
NO >> Check control valve again. Repair or replace control
valve assembly.
Solenoid valve Connector Terminal Resistance (Approx.)
Line pressure solenoid
valveF30 4 - Ground 2.5 - 5 Ω
SCIA3457E
SCIA3275E
SCIA7190E

DTC P0734 A/T 4TH GEAR FUNCTION
AT-133
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Revision: June 20062007 Versa
11 . CHECK DTC
Perform AT-129, "
DTC Confirmation Procedure" .
OK or NG
OK >>INSPECTION END
NG >> Perform AT-61, "
Cruise Test — Part 1" again and return to the start point of this test group.

AT-134
DTC P0740 TORQUE CONVERTER CLUTCH SOLENOID VALVE
Revision: June 20062007 Versa
DTC P0740 TORQUE CONVERTER CLUTCH SOLENOID VALVEPFP:31940
DescriptionUCS005O T

The torque converter clutch solenoid valve is activated, with the gear in D4 and D3 , by the TCM in
response to signals sent from the vehicle speed sensor and the ECM (throttle opening). Lock-up piston
operation will then be controlled.

Lock-up operation, however, is prohibited when A/T fluid temperature is too low.

When the accelerator pedal is depressed (less than 2/8) on lock-up condition, the engine speed should
not change abruptly. If there is an abrupt change in engine speed, there is no lock-up.
CONSULT-II Reference ValueUCS005OU
Remarks: Specification data are reference values.
On Board Diagnosis LogicUCS005OV

This is an OBD-II self-diagnostic item.

Diagnostic trouble code “P0740 T/C CLUTCH SOL/V” with CONSULT-II or 7th judgement flicker without
CONSULT-II is detected when TCM detects an improper voltage drop while it tries to operate solenoid
valve.
Possible CauseUCS005OW

Torque converter clutch solenoid valve

Harness or connector
(The solenoid circuit is open or shorted.)
DTC Confirmation ProcedureUCS005OX
CAUTION:

Always drive vehicle at a safe speed.

If performing this “DTC Confirmation Procedure” again, always turn ignition switch OFF and wait
at least 10 seconds before continuing.
After the repair, perform the following procedure to confirm the malfunction is eliminated.
WITH CONSULT-II
1. Turn ignition switch ON. (Do not start engine.)
2. Select “DATA MONITOR” mode for “A/T” with CONSULT-II and
wait at least 1 second.
3. Touch “START”.
4. Start engine and maintain the following conditions for at least 5
consecutive seconds.
VEHICLE SPEED: 80 km/h (50 MPH) or more
THROTTLE POSI: 0.5/8 - 1.0/8
SLCT LVR POSI: “D” position
Driving location: Driving the vehicle uphill (increased
engine load) will help maintain the driving conditions
required for this test.
5. If the check result is NG, go to AT-136, "
Diagnostic Procedure" .
WITH GST
Follow the procedure “WITH CONSULT-II”.
WITHOUT CONSULT-II
1. Start engine.
2. Drive vehicle in D
1 → D2 → D3 → D4 → D4 lock-up position.
3. Perform self-diagnosis. Refer to AT-90, "
Diagnostic Procedure Without CONSULT-II" .
4. If the check result is NG, go to AT-136, "
Diagnostic Procedure" .
Item name Condition Display value (Approx)
TCC S/V DUTY Lock-up OFF ⇔ Lock-up ON 4% ⇔ 94%
BCIA0031E

DTC P0740 TORQUE CONVERTER CLUTCH SOLENOID VALVE
AT-135
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Revision: June 20062007 Versa
Wiring Diagram — AT — TCVUCS005O Y
BCWA0653E

AT-136
DTC P0740 TORQUE CONVERTER CLUTCH SOLENOID VALVE
Revision: June 20062007 Versa
TCM terminal data are reference values, measured between each terminal and ground.
Diagnostic ProcedureUCS005O Z
1. CHECK INPUT SIGNAL
With CONSULT-II
1. Start engine.
2. Select “MAIN SIGNALS” in “DATA MONITOR” mode for “A/T” with CONSULT-II.
3. Read out the value of “TCC S/V DUTY” while driving. Check the
value changes according to driving speed.
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.
2. CHECK TORQUE CONVERTER CLUTCH SOLENOID VALVE CIRCUIT
1. Turn ignition switch OFF.
2. Disconnect TCM connector.
3. Check resistance between TCM connector terminal and ground.
OK or NG
OK >> GO TO 5.
NG >> GO TO 3.
Terminal Wire color Item ConditionJudgement standard
(Approx.)
3GRTorque converter clutch
solenoid valveWhen A/T performs lock-up. 8 - 15 V
When A/T does not perform lock-up. 0 V
Monitor item ConditionDisplay value
(Approx)
TCC S/V DUTY Lock-up OFF ⇔ Lock-up ON 4 % ⇔ 94 %
SCIA3257E
NameConnec-
torTerminal ConditionJudgement
standard
(Approx.)
Torque con-
verter clutch
solenoid
valveE31 3 - GroundWhen A/T performs lock-
up.8 - 15 V
When A/T does not per-
form lock-up.0 V
SCIA3261E
Solenoid Valve Connector Terminal Resistance (Approx.)
Torque converter clutch
solenoid valveE31 3 - Ground 5 - 20 Ω
SCIA3262E

DTC P0740 TORQUE CONVERTER CLUTCH SOLENOID VALVE
AT-137
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Revision: June 20062007 Versa
3. CHECK HARNESS BETWEEN TCM AND TERMINAL CORD ASSEMBLY HARNESS CONNECTOR
1. Turn ignition switch OFF.
2. Disconnect terminal cord assembly harness connector and TCM connector.
3. Check continuity between terminal cord assembly harness con-
nector terminal and TCM connector terminal.
4. If OK, check harness for short to ground and short to power.
5. If OK, check continuity between ground and transaxle assembly.
6. Reinstall any part removed.
OK or NG
OK >> GO TO 4.
NG >> Repair open circuit or short to ground or short to power in harness or connectors.
4. CHECK VALVE RESISTANCE
1. Turn ignition switch OFF.
2. Disconnect terminal cord assembly connector in engine room.
3. Check resistance between terminal cord assembly harness con-
nector terminal and ground.
OK or NG
OK >> GO TO 5.
NG >> Repair or replace damaged parts.
5. CHECK DTC
Perform AT-134, "
DTC Confirmation Procedure" .
OK or NG
OK >>INSPECTION END
NG >> GO TO 6.
6. CHECK TCM
1. Check TCM input/output signal. Refer to AT-78, "
TCM Terminals and Reference Value" .
2. If NG, recheck TCM pin terminals for damage or loose connection with harness connector.
OK or NG
OK >>INSPECTION END
NG >> Repair or replace damaged parts.
Item Connector Terminal Continuity
TCM E31 3
Ye s
Terminal cord assembly
harness connectorF30 5
SCIA3263E
Solenoid valve Connector Terminal Resistance (Approx.)
Torque converter clutch
solenoid valveF30 5 - Ground 5 - 20 Ω
SCIA3456E