NISSAN TEANA 2003 Service Manual

DTC P1777 STEP MOTOR - CIRCUIT
CVT-155
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CVT

TCM terminals data are reference values.
Diagnostic ProcedureBCS001LY
1. CHECK INPUT SIGNAL
With CONSULT-II
1. Start engine.
2. Select “SELECTION FROM MENU” in “DATA MONITOR” mode
for “TRANSMISSION” with CONSULT-II.
3. Start vehicle and read out the value of “STM STEP”, “SMCOIL
A”, “SMCOIL B”, “SMCOIL C”, and “SMCOIL D”.
OK or NG
OK >> GO TO 4.
NG >> GO TO 2.
2. CHECK HARNESS BETWEEN TCM AND STEP MOTOR
1. Turn ignition switch OFF.
2. Disconnect CVT unit connector and TCM 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. If OK, check continuity between body ground and CVT assembly.
6. Reinstall any part removed.
OK or NG
OK >> GO TO 3.
NG >> Repair open circuit or short to ground or short to power in harness or connectors.
Terminal Wire color Item Condition Data (Approx.)
11 G/R Step motor A Within 2 seconds after ignition switch ON, the time measure-
ment by using the pulse width measurement function (Hi level) of
CONSULT-II.*1
CAUTION:
Connect the diagnosis data link cable to the vehicle diagno-
sis connector.
*1: A circuit tester cannot be used to test this item.30.0 msec
12 O/B Step motor B10.0 msec
20 R Step motor C30.0 msec
21 R/G Step motor D10.0 msec
Item name Condition Display value (Approx.)
STM STEP
During driving−20 step - 190 step
SMCOIL A
Changes ON⇔OFF SMCOIL B
SMCOIL C
SMCOIL D
SCIA4516E
Item Connector Terminal Continuity
TCM F106 11
Ye s
CVT unit harness connector F49 6
TCM F106 12
Ye s
CVT unit harness connector F49 7
TCM F106 20
Ye s
CVT unit harness connector F49 8
TCM F106 21
Ye s
CVT unit harness connector F49 9
SCIA4695E

CVT-156
DTC P1777 STEP MOTOR - CIRCUIT

3. CHECK STEP MOTOR
Check step motor Refer to CVT-156, "
Component Inspection" .
OK or NG
OK >> GO TO 4.
NG >> Repair or replace damaged parts.
4. CHECK DTC
Perform “DTC Confirmation Procedure”. Refer to CVT-153, "
DTC Confirmation Procedure" .
OK or NG
OK >>INSPECTION END
NG >> GO TO 5.
5. CHECK TCM
1. Check TCM input/output signal. Refer to CVT-40, "
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 >> Repair or replace damaged parts.
Component InspectionBCS001LZ
STEP MOTOR
1. Turn ignition switch OFF.
2. Disconnect CVT unit harness connector.
3. Check resistance between CVT unit harness connector termi-
nals and ground.
4. If NG, replace the transaxle assembly. Refer to CVT-193, "
Removal and Installation" .
Control valve Connector TerminalResistance
(Approx.)
Step motor F496 - 7
30 Ω
8 - 9
6 - Ground
15 Ω 7 - Ground
8 - Ground
9 - Ground
SCIA4696E

DTC P1778 STEP MOTOR - FUNCTION
CVT-157
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DTC P1778 STEP MOTOR - FUNCTIONPFP:31947
DescriptionBCS001M0

The step motor's 4 aspects of ON/OFF change according to the signal from TCM. As a result, the flow of
line pressure to primary pulley is changed and pulley ratio is controlled.

This diagnosis item is detected when electrical system is OK, but mechanical system is NG.

This diagnosis item is detected when the state of the changing the speed mechanism in unit does not
operate normally.
CONSULT-II Reference ValueBCS001M1
Remarks: Specification data are reference values.
On Board Diagnosis LogicBCS001M2
Diagnostic trouble code “P1778 STEP MOTR/FNC” with CONSULT-II is detected under the following condi-
tions.

When not changing the pulley ratio according to the instruction of TCM.
Possible CauseBCS001M3
Ste p mo to r
DTC Confirmation ProcedureBCS001M4
CAUTION:

Always drive vehicle at a safe speed.

Before starting “DTC Confirmation Procedure”, confirm “Hi” or “Mid” or “Low” fixation by “PRI
SPEED” and “VEHICLE SPEED” on “DATA MONITOR MODE”.

If hi-geared fixation occurred, go to CVT-158, "Diagnostic Procedure" .
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, touch “ERASE” on “SELF-DIAG RESULTS” and then perform the following procedure to con-
firm 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 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)
3. Select “DATA MONITOR” mode for “TRANSMISSION” with
CONSULT-II.
4. Start engine and maintain the following conditions for at least 30
consecutive seconds.
TEST START FROM 0 km/h (0 MPH)
CONSTANT ACCELERATION: Keep 30 sec or more
VEHICLE SPEED: 10 km/h (6 MPH) or more
ACC PEDAL OPEN: More than 1.0/8
RANGE: “D” position
ENG SPEED: 450 rpm or more
5. If DTC is detected, go to CVT-158, "
Diagnostic Procedure" .
Item name Condition Display value (Approx.)
STM STEP
During driving−20 step - 190 step
GEAR RATIO2.37 - 0.43
BCIA0031E

CVT-158
DTC P1778 STEP MOTOR - FUNCTION

Diagnostic ProcedureBCS001M5
1. CHECK STEP MOTOR
With CONSULT-II
It is monitoring whether “GEAR RATIO: 2.37 - 0.43” changes similarly to “STM STEP: −20 - 190” by “DATA
MONITOR” mode. Refer to CVT-50, "
DATA MONITOR MODE" .
Without CONSULT-II
Inspect the engine speed (rise and descend), vehicle speed, throttle position, and check shift change. Refer to
CVT-198, "
Vehicle Speed at Which Gear Shifting Occurs" .
OK or NG
OK >>INSPECTION END
NG >> Replace the transaxle assembly. Refer to CVT-193, "
Removal and Installation" .

CVT INDICATOR CIRCUIT
CVT-159
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CVT

CVT INDICATOR CIRCUITPFP:24810
DescriptionBCS001M6
TCM sends the switch signals to unified meter and A/C amp via CAN communication line. Then manual mode
switch position is indicated on the CVT indicator.
CONSULT-II Reference ValueBCS001M7
Diagnostic ProcedureBCS001M8
1. CHECK INPUT SIGNAL
With CONSULT-II
1. Start engine.
2. Select “MAIN SIGNALS” in “DATA MONITOR” mode for “TRANSMISSION” with CONSULT-II and read
out the value of “M GEAR POS”.
3. Drive vehicle in the manual mode, and confirm that the actual gear position and the meter's indication of
the position mutually coincide when the select lever is shifted to the “+ (up)” or “- (down)” side (1st ⇔ 6th
gear).
OK or NG
OK >>INSPECTION END
NG >> Check the following.
CVT INDICATOR SYMPTOM CHART
Item name Condition Display value
M GEAR POS During driving 1, 2, 3, 4, 5, 6
Items Presumed location of trouble
The actual gear position does not change, or shifting into the
manual mode is not possible (no gear shifting in the manual mode
possible).
The shift position indicator is not indicated.

Manual mode switch
Refer to CVT-113, "
DTC P0826 MANUAL MODE SWITCH
CIRCUIT" .

CVT main system (Fail-safe function actuated)
Refer to CVT-47, "
SELF-DIAGNOSTIC RESULT MODE" .
The actual gear position changes, but the shift position indicator
is not indicated.Perform the self-diagnosis function.
Refer to CVT-47, "
SELF-DIAGNOSTIC RESULT MODE" .
The actual gear position and the indication on the shift position
indicator do not coincide.Perform the self-diagnosis function.
Refer to CVT-47, "
SELF-DIAGNOSTIC RESULT MODE" .
Only a specific position or positions is/are not indicated on the
shift position indicator.Check the meter control unit.
Refer to DI-4, "
COMBINATION METERS" .

CVT-160
TROUBLE DIAGNOSIS FOR SYMPTOMS

TROUBLE DIAGNOSIS FOR SYMPTOMSPFP:00007
Wiring Diagram — CVT — NONDTCBCS001M9
TCWM0545E

TROUBLE DIAGNOSIS FOR SYMPTOMS
CVT-161
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CVT

TCWM0546E

CVT-162
TROUBLE DIAGNOSIS FOR SYMPTOMS

TCWM0547E

TROUBLE DIAGNOSIS FOR SYMPTOMS
CVT-163
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TCM terminal data are reference values, measured between each terminal and ground.
TerminalWire
colorItem Condition Data (Approx.)
5 L CAN-H — —
6 P CAN-L — —
8GBack-up lamp
relaySelector lever in “R” position. 0 V
Selector lever in other positions. Battery voltage
13 G/W ROM assembly — —
14 L/R ROM assembly — —
15 BR/R ROM assembly — —
31 O K-LINE — —
42 W/R Sensor ground Always 0 V
46 L/O Sensor power— 5.0 V
—0 V

CVT-164
TROUBLE DIAGNOSIS FOR SYMPTOMS

CVT Indicator Lamp Does Not Come OnBCS001MB
SYMPTOM:
CVT indicator lamp does not come on for about 2 seconds when turning ignition switch to ON.
DIAGNOSTIC PROCEDURE
1. CHECK CAN COMMUNICATION LINE
Perform the self-diagnosis check. Refer to CVT-47, "
SELF-DIAGNOSTIC RESULT MODE" .
Is any malfunction of the
“U1000 CAN COMM CIRCUIT” indicated in the results?
YES >> Check CAN communication line. Refer to CVT-53, "DTC U1000 CAN COMMUNICATION LINE" .
NO >> GO TO 2.
2. CHECK TCM POWER SOURCE
1. Turn ignition switch ON.
2. Check voltage between TCM connector terminals and ground.
Refer to CVT-135, "
Wiring Diagram — CVT — POWER" .
OK or NG
OK >> GO TO 4.
NG >> GO TO 3.
3. DETECT MALFUNCTIONING ITEM
Check the following.

Harness for short or open between ignition switch and TCM connector terminal 10, 19
Refer to CVT-135, "
Wiring Diagram — CVT — POWER" .

10A fuse (No.83, located in the IPDM E/R). Refer to CVT-135, "Wiring Diagram — CVT — POWER" .

Ignition switch. Refer to PG-3, "POWER SUPPLY ROUTING CIRCUIT" .
OK or NG
OK >> GO TO 4.
NG >> Repair or replace damaged parts.
4. CHECK TCM GROUND CIRCUIT
1. Turn ignition switch OFF.
2. Disconnect TCM connector.
3. Check continuity between TCM connector terminals and ground.
Refer to CVT-135, "
Wiring Diagram — CVT — POWER" .
OK or NG
OK >> GO TO 5.
NG >> Repair open circuit or short to ground or short to power
in harness or connectors.
Name Connec-
tor Terminal Voltage (Approx.)
Power supply F10610 Battery voltage
19 Battery voltage
SCIA4737E
Name Connec-
tor Terminal Continuity
Ground F10725
Ye s
48
SCIA2671E