P1574
ASCD Vehicle Speed Sensor
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The P1574 code on Nissan vehicles indicates a problem with the ASCD (Automatic Speed Control Device) vehicle speed sensor system. The ECM receives two independent vehicle speed signals — one from the transmission control module and one derived from the ABS wheel speed sensors — via the CAN communication network. When the ECM detects a significant discrepancy between these two speed values, it sets P1574 and disables cruise control.
The most noticeable symptom is that your cruise control stops working. The speedometer may also behave erratically in some cases. This code does not typically affect engine performance or drivability, but losing cruise control is inconvenient, especially for highway driving. Speed-dependent automatic features like auto door locks may also behave inconsistently.
Diagnosis should focus on identifying which speed signal is incorrect. Start with the ABS wheel speed sensors — a damaged or contaminated sensor on one wheel will produce a speed reading that differs from the transmission speed sensor. Check each sensor for damage, proper air gap, and clean the sensor faces. If all ABS sensors check out, inspect the CAN bus wiring between the relevant modules. The repair is usually affordable at $20–$100 for DIY (sensor replacement) or $100–$350 professionally.
Severity
Symptoms
- •Cruise control does not work or disengages unexpectedly
- •Check engine light is on
- •Speedometer reading may be erratic or inaccurate
- •Speed-dependent features like auto door locks may behave oddly
- •No significant engine performance issues
- •ASCD or cruise control indicator light may flash
Likely Causes
The ECM detects a difference between the vehicle speed reported by the transmission speed sensor and the speed calculated from ABS wheel speed sensors. This mismatch, often caused by a faulty ABS sensor, triggers the code.
One or more ABS wheel speed sensors are providing inaccurate speed data due to damage, contamination, or air gap issues, creating a mismatch with the transmission speed signal.
The CAN bus wiring between the combination meter, TCM, and ECM has an open or short circuit, preventing accurate speed data from reaching the ASCD system.
The combination meter that processes and relays vehicle speed information has an internal fault, providing incorrect speed data to the ECM.
Estimated Cost
Professional Repair
Includes parts + labor
Common Fixes
- Inspect and replace faulty ABS wheel speed sensor(s)
- Check CAN bus wiring for open or short circuits
- Inspect and clean speed sensor connectors for corrosion
- Replace the vehicle speed sensor if faulty