Nissan Altima (L32) 2007-2012 Service Manual: 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 controlled.
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 ignition switch OFF.
Then wait at least 10 seconds before performing the next test.
1.CHECK DTC DETECTION
1. Start engine.
2. Drive vehicle for at least 5 consecutive seconds.
3. Perform “SELF-DIAG RESULTS” mode for “TRANSMISSION”.
Follow the procedure “With CONSULT-III”.
Is “P1777 STEP MOTR CIRC” detected? YES >> Go to TM-184, "Diagnosis Procedure".
NO >> Check intermittent incident. Refer to GI-42, "Intermittent Incident".
Diagnosis Procedure
1.CHECK STEP MOTOR CIRCUIT
1. Turn ignition switch OFF.
2. Disconnect TCM harness connector.
3. Check resistance between TCM harness connector F16 terminal 27, 29 and 28, 30.
4. Check resistance between TCM harness connector F16 terminal 27, 28, 29, 30 and ground.
Is the inspection result normal? YES >> GO TO 5.
NO >> GO TO 2.
2.CHECK HARNESS BETWEEN TCM AND CVT UNIT (STEP MOTOR) (PART 1)
1. Disconnect CVT unit harness connector.
2. Check continuity between TCM harness connector F16 (A) terminal 27, 28, 29, 30 and CVT unit harness connector F46 (B) terminal 9, 8, 7, 6.
Is the inspection result normal? YES >> GO TO 3.
NO >> Repair or replace damaged parts.
3.CHECK HARNESS BETWEEN TCM AND CVT UNIT (STEP MOTOR) (PART 2)
Check continuity between TCM harness connector F16 terminal 27, 28, 29, 30 and ground.
Is the inspection result normal? YES >> GO TO 4.
NO >> Repair or replace damaged parts.
4.CHECK STEP MOTOR
Check step motor. Refer to TM-186, "Component Inspection (Step Motor)".
Is the inspection result normal? YES >> GO TO 5.
NO >> Replace transaxle assembly. Refer to TM-259, "Exploded View".
5.DETECT MALFUNCTIONING ITEMS
Check TCM connector pin terminals for damage or loose connection with harness connector.
Is the inspection result normal?
Check TCM connector pin terminals for damage or loose connection with harness connector.
Is the inspection result normal?
Component Inspection (Step Motor)
1.CHECK STEP MOTOR
1. Check resistance between CVT unit terminal 6, 8 and 7, 9.
2. Check resistance between CVT unit terminal 6, 7, 8, 9 and ground.
Is the inspection result normal? YES >> INSPECTION END
NO >> Replace transaxle assembly. Refer to TM-259, "Exploded View".
P1745 line pressure control
Description
The pressure control solenoid valve A (line pressure solenoid valve)
regulates the oil pump discharge pressure
to suit the driving condition in response to a signal sent from the TCM. ...
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.
...
Other materials:
Service information for electrical
incident
Work Flow
Control Units and Electrical Parts
PRECAUTIONS
• Never reverse polarity of battery terminals.
• Install only parts specified for a vehicle.
• Before replacing the control unit, check the input and output and functions of
the component parts.
• Do not apply excessi ...
B260A ignition relay
Description
BCM turns ON the following relays to ignition power supply to each ECU when
the ignition switch is turned
ON.
• Ignition relay-1 (inside IPDM E/R)
• Ignition relay-2 (inside fuse box)
• Blower fan motor relay
BCM checks any ignition relay ON request for consistency with ...
P0850 PNP Switch
Description
When the shift lever position is P or N (CVT), Neutral position (M/T),
park/neutral position (PNP) switch is ON.
ECM detects the position because the continuity of the line (the ON signal)
exists.
DTC Logic
DTC DETECTION LOGIC
DTC CONFIRMATION PROCEDURE
1.INSPECTION START
...
