Nissan Juke Service and Repair Manual : P1778 step motor
Description
• 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.
DTC Logic
DTC DETECTION LOGIC

DTC CONFIRMATION PROCEDURE
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 TM-252, "Diagnosis 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, perform the following procedure to confirm the malfunction is eliminated.
1.CHECK DTC DETECTION
With CONSULT-III
1. Turn ignition switch ON.
2. Select “Self Diagnostic Results” in “TRANSMISSION”.
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 30 consecutive seconds.
TEST START FROM 0 km/h (0 MPH)
CONSTANT ACCELERATION : Keep 30 seconds 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
With GST.
Follow the procedure “With CONSULT-III”.
Is “P1778” detected? YES >> Go to TM-252, "Diagnosis Procedure".
NO >> Check intermittent incident. Refer to GI-42, "Intermittent Incident".
Diagnosis Procedure
1.CHECK STEP MOTOR
With CONSULT-III
It is monitoring whether “GEAR RATIO: 2.34 – 0.39” changes similarly to “STM STEP: 0 – 177” by “DATA MONITOR” mode.
Without CONSULT-III
Inspect the engine speed (rise and descend), vehicle speed, throttle position, and check shift change. Refer to TM-308, "Shift Characteristics".
Is the inspection result normal? YES >> Check intermittent incident. Refer to GI-42, "Intermittent Incident".
NO >> Replace the transaxle assembly. Refer to TM-301, "Removal and Installation".
P1777 step motor
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
ignit ...
Shift position indicator circuit
Description
• TCM sends position indicator signals to combination meter by CAN
communication line.
• Manual mode switch position is indicated on shift position indicator
Component Function Check
...
Other materials:
Diagnosis system (EPS control unit)
Consult-III Function
FUNCTION
CONSULT-III can display each diagnostic item using the diagnostic test modes
shown following.
*: The following diagnosis information is erased by erasing.
• DTC
• Freeze frame data (FFD)
ECU IDENTIFICATION
Displays the part number stored in the control unit.
...
Ecu diagnosis information
BCM
Reference Value
VALUES ON THE DIAGNOSIS TOOL
CONSULT-III MONITOR ITEM
TERMINAL LAYOUT
PHYSICAL VALUES
• *1: With manual A/C
• *2: RHD models
• *3: M/T models
• *4: LHD models
• *5: Except M/T models
Fail-safe
FAIL-SAFE CONTROL BY DTC
B ...
ECU diagnosis information
ECM
Reference Value
VALUES ON THE DIAGNOSIS TOOL
Remarks:
• Specification data are reference values.
• Specification data are output/input values which are detected or supplied by
the ECM at the connector.
*Specification data may not be directly related to their components
signals/values/o ...
