Nissan Maxima Service and Repair Manual: P1574 ASCD vehicle speed sensor

Description

The ECM receives two vehicle speed signals via the 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-68, "System Diagram" for ASCD functions.

DTC Logic

DTC DETECTION LOGIC

NOTE:

•  If DTC P1574 is displayed with DTC UXXXX, first perform the trouble diagnosis for DTC UXXXX.
• If DTC P1574 is displayed with DTC P0500, first perform the trouble diagnosis for DTC P0500. Refer to EC-378, "DTC Logic".
• If DTC P1574 is displayed with DTC P0605, first perform the trouble diagnosis for DTC P0605. Refer to EC-391, "DTC Logic".
• If DTC P1574 is displayed with DTC P0607, first perform the trouble diagnosis for DTC P0607. Refer to EC-393, "DTC Logic".

DTC CONFIRMATION PROCEDURE

1.PRECONDITIONING

If DTC Confirmation Procedure has been previously conducted, always perform the following before conducting the next test.

1. Turn ignition switch OFF and wait at least 10 seconds.
2. Turn ignition switch ON.
3. Turn ignition switch OFF and wait at least 10 seconds.

2.PERFORM DTC CONFIRMATION PROCEDURE

1. Start engine (VDC switch OFF).
2. 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.

3. Check DTC.

Diagnosis Procedure

1.CHECK DTC WITH TCM

Check DTC with TCM.

2.CHECK DTC WITH "ABS ACTUATOR AND ELECTRIC UNIT (CONTROL UNIT)"

3.CHECK COMBINATION METER FUNCTION

P1700 CVT CONTROL SYSTEM

Description

This DTC is displayed with other DTC regarding TCM. Perform the trouble diagnosis for corresponding DTC.

Refer to EC-542, "DTC Index". When this DTC is detected, the ASCD control is canceled.