Nissan Sentra Service Manual: P1574 ASCD Vehicle speed sensor
Description
The ECM receives two vehicle speed sensor signals via CAN communication line. One is sent from combination meter, and the other is from TCM (Transmission control module). The ECM uses these signals for ASCD control. Refer to EC-51, "AUTOMATIC SPEED CONTROL DEVICE (ASCD) : System Description" for ASCD functions.
DTC Logic
DTC DETECTION LOGIC
NOTE:
- If DTC P1574 is displayed with DTC U1001, first perform the trouble diagnosis for DTC U1001. Refer to EC-168, "DTC Logic".
- If DTC P1574 is displayed with DTC P0500, first perform the trouble diagnosis for DTC P0500. Refer to EC-330, "EXCEPT FOR M/T MODELS : DTC Logic".
- If DTC P1574 is displayed with DTC P0605, first perform the trouble diagnosis for DTC P0605. Refer to EC-348, "DTC Logic".
- If DTC P1574 is displayed with DTC P0607, first perform the trouble diagnosis for DTC P0607. Refer to EC-350, "DTC Logic".
| DTC No. | CONSULT screen terms (Trouble diagnosis content) | DTC detecting condition | Possible cause |
| P1574 | ASCD VHL SPD SEN (ASCD VHL SPD SEN) | ECM detects a difference between two vehicle speed signals is out of the specified range. |
|
DTC CONFIRMATION PROCEDURE
1.PRECONDITIONING
If DTC Confirmation Procedure has been previously conducted, always perform the following procedure before conducting the next test.
- Turn ignition switch OFF and wait at least 10 seconds.
- Turn ignition switch ON.
- Turn ignition switch OFF and wait at least 10 seconds.
>> GO TO 2.
2.PERFORM DTC CONFIRMATION PROCEDURE
- Start engine.
- Drive the vehicle at more than 40 km/h (25 MPH).
CAUTION:
Always drive vehicle at a safe speed.
NOTE:
This procedure may be conducted with the drive wheels lifted in the shop or by driving the vehicle.
If a road test is expected to be easier, it is unnecessary to lift the vehicle.
- Check DTC.
Is DTC detected? YES >> Proceed to EC-397, "Diagnosis Procedure".
NO >> INSPECTION END
Diagnosis Procedure
1.CHECK DTC WITH TCM
Check DTC with TCM. Refer to TM-108, "CONSULT Function".
Is DTC detected?
NO >> GO TO 2.
YES >> Perform trouble shooting relevant to DTC indicated.
2.CHECK DTC WITH “ABS ACTUATOR AND ELECTRIC UNIT (CONTROL UNIT)”
Check DTC with ABS actuator and electric unit (control unit). Refer to BRC-31, "CONSULT Function (ABS)".
Is DTC detected? NO >> INSPECTION END
YES >> Perform trouble shooting relevant to DTC indicated.
P1572 ASCD Brake switch
DTC Logic
DTC DETECTION LOGIC
NOTE:
If DTC P1572 is displayed with DTC P0605, first perform the trouble
diagnosis for DTC P0605. Refer
to EC-348, "DTC Logic".
This self-diagnosi ...
P1650 Starter motor relay 2
Description
ECM controls ON/OFF state of the starter relay, according to the engine and
vehicle condition. ECM transmits
a control signal to IPDM E/R via BCM by CAN communication.
Under normal ...
Other materials:
Diagnosis description : system readiness
test (SRT) code
System Readiness Test (SRT) code is specified in Service $01 of SAE J1979/ISO
15031-5.
As part of an enhanced emissions test for Inspection & Maintenance (I/M),
certain states require the status of
SRT be used to indicate whether the ECM has completed self-diagnosis of major
emission s ...
Basic inspection
Diagnosis and repair workflow
Trouble diagnosis flow chart
Trouble diagnosis procedure
Interview with customer
Interview with the customer is important to detect the root cause of can
communication system errors and to
understand vehicle condition and symptoms for proper trouble diagnosi ...
Getting started
The following procedures will help you get
started using the Bluetooth® Hands-Free Phone
System with NISSAN Voice Recognition. For additional
command options, refer to “List of voice
commands” in this section.
Choosing a language
You can interact with the Bluetooth® Hands-
Free Phone Sy ...
