ASCD Vehicle Speed Sensor

P1574 ASCD VEHICLE SPEED SENSOR

Description
The ECM receives two vehicle speed signals via the CAN communication line. One is sent from "unified meter and A/C amp.", and the other is from TCM (Transmission control module). The ECM uses these signals for
ASCD control. System Description 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. P0500 (A/T models) or P0500 (M/T models).
- If DTC P1574 is displayed with DTC P0605, first perform the trouble diagnosis for DTC P0605. P0605.
- If DTC P1574 is displayed with DTC P0607, first perform the trouble diagnosis for DTC P0607. P0607.

DTC CONFIRMATION PROCEDURE
1.PRECONDITIONING
If DTC Confirmation Procedure has been previously conducted, always perform the following procedure 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.
- GO TO 2.
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.
Is DTC detected?
YES - Go to SEE Diagnosis Procedure.
NO - INSPECTION END

Diagnosis Procedure
1.CHECK DTC WITH TCM
Check DTC with TCM. Reading and Clearing Diagnostic Trouble Codes.
Is the inspection result normal?
YES - GO TO 2.
NO - Perform trouble shooting relevant to DTC indicated.
2.CHECK DTC WITH "ABS ACTUATOR AND ELECTRIC UNIT (CONTROL UNIT)"
Scan Tool Testing and Procedures.
Is the inspection result normal?
YES - GO TO 3.
NO - Repair or replace.
3.CHECK DTC WITH "UNIFIED METER AND A/C AMP."
.
- INSPECTION END