Cruise Control System - Vehicle Speed Too High
Diagnostic trouble code P0574 indicates that the powertrain control module (PCM) has detected the vehicle speed is too high for the cruise control system to operate safely. The PCM sets this code when the vehicle exceeds the maximum allowable speed limit programmed for cruise control engagement.
This code is generally a low priority as it primarily affects the cruise control system. The vehicle remains safe to drive, but cruise control will be disabled until the issue is resolved or the speed is reduced.
Common symptoms
- Cruise control system is inoperative
- Cruise control disengages unexpectedly
- Check Engine Light (MIL) is illuminated
- Cruise control indicator light flashes or turns off
- Inability to set a cruising speed
Likely causes
- Driver attempting to set cruise control above the maximum allowed speed
- Faulty vehicle speed sensor (VSS)
- Wiring or connector issues in the vehicle speed sensor circuit
- Incorrect tire size affecting speed readings
- Faulty cruise control module or switch
- Powertrain Control Module (PCM) software issue or failure
What to check before replacing parts
Verify the vehicle speed when attempting to use cruise control.
Look for: Ensure the driver is not attempting to engage the cruise control at a speed higher than the manufacturer's maximum limit (often around 85-90 mph).
Scan for other related diagnostic trouble codes, especially vehicle speed sensor (VSS) codes.
Look for: The presence of VSS codes (e.g., P0500) indicates the speed sensor or its circuit is likely the root cause rather than just driver behavior.
Monitor the vehicle speed sensor data PID using a scan tool while driving.
Look for: The speed displayed on the scan tool should match the speedometer and actual vehicle speed smoothly without erratic jumps or dropouts.
Inspect the wiring harness and connectors for the vehicle speed sensor.
Look for: Look for chafed wires, corrosion, loose connections, or damage that could cause intermittent or incorrect speed signals to the PCM.
Check the vehicle's tire size against the manufacturer's specifications.
Look for: Significantly oversized or undersized tires can alter the actual vehicle speed versus the calculated speed, potentially triggering the code.
This page explains the generic P0574 definition and is general reference information, not a diagnosis for your specific vehicle. Actual causes, severity, and repairs vary by make, model, engine, and mileage — always confirm with a scan tool and a qualified technician before replacing parts.
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