Nissan Altima 2007-2012 Service Manual: P1778 step motor - function

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-364, "Diagnosis Procedure".

NOTE: If “DTC CONFIRMATION PROCEDURE” has been previously performed, always turn ignition switch OFF.

Then wait at least 10 seconds before performing the next test.

1.CHECK DTC DETECTION

1. Turn ignition switch ON.

2. Select “DATA MONITOR”.

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.

Follow the procedure “With CONSULT-III”.

Is “P1778 STEP MOTR/FNC” detected? YES >> Go to TM-364, "Diagnosis Procedure".

NO >> Check intermittent incident. Refer to GI-42, "Intermittent Incident".

Diagnosis Procedure

1.CHECK STEP MOTOR SYSTEM

Check step motor system. Refer to TM-361, "Description".

Is the inspection result normal?

YES >> GO TO 2.

NO >> Repair or replace damaged parts.

2.CHECK INPUT SPEED SENSOR (PRIMARY SPEED SENSOR) SYSTEM

Check input speed sensor (primary speed sensor) system. Refer to TM-313, "Description".

Is the inspection result normal? YES >> GO TO 3.

NO >> Repair or replace damaged parts.

3.CHECK OUTPUT SPEED SENSOR (SECONDARY SPEED SENSOR) SYSTEM

Check output speed sensor (secondary speed sensor) system. Refer to TM-318, "Description".

Is the inspection result normal? YES >> GO TO 4.

NO >> Repair or replace damaged parts.

4.DETECT MALFUNCTIONING ITEMS

Check TCM connector pin terminals for damage or loose connection with harness connector.

Is the inspection result normal? YES >> Replace TCM. Refer to TM-430, "Exploded View".

NO >> Repair or replace damaged parts.

    P1777 step motor
    Description The step motor changes the step with turning 4 coils ON/OFF according to the signal from TCM. As a result, the flow of line pressure to primary pulley is changed and pulley ratio is ...

    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 Functio ...

    Other materials:

    P0506 ISC System
    Description The ECM controls the engine idle speed to a specified level through the fine adjustment of the air, which is let into the intake manifold, by operating the electric throttle control actuator. The operating of the throttle valve is varied to allow for optimum control of the engine ...

    Power generation voltage variable control system operation inspection
    Inspection Procedure CAUTION: When performing this inspection, always use a charged battery that has completed the battery inspection. (When the charging rate of the battery is low, the response speed of the voltage change will become slow. This can cause an incorrect inspection.) 1.CHECK ...

    P0128 Thermostat function
    DTC Logic DTC DETECTION LOGIC NOTE: If DTC P0128 is displayed with DTC P0300, P0301, P0302, P0303, P0304, P0305 or P0306, first perform the trouble diagnosis for DTC P0300, P0301, P0302, P0303, P0304, P0305, P0306. Refer to EC-1283, "DTC Logic". Engine coolant temperature has n ...