P0574
UniversalA P0574 diagnostic trouble code indicates that the Powertrain Control Module (PCM) has detected an input from the cruise control system that suggests the vehicle speed is exceeding a calibrated limit, or there is an inconsistency in speed readings related to the cruise control system.
Medium SeverityThe P0574 code signifies that your car's computer has detected an unusually high speed reading from the cruise control system, possibly exceeding its operational limits or disagreeing with other speed sensors. This can lead to the cruise control system becoming inoperative, affecting driver convenience during highway travel.
⚠️ Before You Begin (Safety First)
Always turn off the ignition and disconnect the battery before attempting any electrical repairs. Exercise caution when diagnosing speed-related issues, as improper repairs could lead to unexpected vehicle behavior or loss of cruise control functionality at critical moments.
Common Symptoms
- Cruise control system is inoperative
- Check Engine Light (MIL) illuminated
- Erratic or inaccurate speedometer readings
- Brake lights not functioning correctly (if related to brake switch issue)
Common Causes
- Faulty cruise control switch or buttons
- Malfunctioning brake light switch (often used to disengage cruise control)
- Defective Vehicle Speed Sensor (VSS)
- Wiring harness issues (chafed, shorted, or open circuits)
- Blown fuse for the cruise control system
- Faulty Powertrain Control Module (PCM) - rare
Frequently reported on: Ford F-150 (2004-2008), Honda Accord (2003-2007), Chevrolet Silverado (2000-2006), Toyota Camry (2007-2011)
Diagnostic Steps
- Check all fuses related to the cruise control system and brake lights.
- Inspect the brake light switch for proper operation and adjustment.
- Test the cruise control ON/OFF and SET/RESUME switches for continuity.
- Visually inspect wiring harnesses and connectors for damage or corrosion, especially around the VSS and cruise control components.
- If accessible, inspect and potentially clean the Vehicle Speed Sensor (VSS) and its connector.
👨🔧 When to Call a Professional
If you experience any sudden or unexpected acceleration when cruise control is engaged, or if the cruise control system fails to disengage properly with the brake pedal or switch, seek professional assistance immediately as this could be a severe safety hazard.
Commonly Asked Questions
Can I drive my car with a P0574 code?
Yes, you can typically drive with a P0574 code, but your cruise control system will likely be inoperative. It's advisable to diagnose and repair it promptly to avoid potential issues with speed readings or brake light functionality.
What is the most common cause of a P0574 code?
The most common causes are often a faulty brake light switch or issues with the cruise control switch itself. Problems with the Vehicle Speed Sensor or its wiring are also frequent contributors.
Does a P0574 code affect my car's performance?
A P0574 code primarily affects the cruise control system. However, if the underlying cause is a faulty Vehicle Speed Sensor, it could potentially impact speedometer accuracy or automatic transmission shift points, though direct engine performance is usually not affected.
How do I clear the P0574 code after fixing the issue?
After repairing the problem, the code can be cleared using an OBD-II scanner. In some cases, disconnecting the vehicle's battery for a short period (15-30 minutes) can also clear codes, but this may reset other vehicle systems.
Is a P0574 code a safety concern?
While often related to convenience, it can be a safety concern if the cruise control system malfunctions unexpectedly (e.g., sticks at a high speed) or if a faulty brake light switch prevents your brake lights from illuminating, increasing the risk of a rear-end collision.