What Does P0566 Mean?
The ECM has detected a malfunction in the cruise control OFF signal circuit. The system is not receiving a valid OFF/cancel signal from the cruise control switches when the driver attempts to deactivate cruise control. This could mean the OFF switch is stuck, the signal wire is open, or the ECM is not receiving the expected voltage change when the OFF button is pressed.
Common Causes
40%
Faulty cruise control OFF/cancel switch with stuck or worn contacts that do not produce a valid OFF signal
25%
Open circuit in the cruise control OFF signal wire preventing the cancel command from reaching the ECM
25%
Clock spring failure breaking the OFF signal path from steering wheel switch to body harness
10%
ECM software or input circuit fault preventing recognition of the OFF signal voltage transition
Diagnostic Steps
1
Step 1: Verify the cruise control OFF/cancel button has tactile feedback when pressed and is not physically stuck or jammed. Inspect for spilled drinks or debris in the switch mechanism.
2
Step 2: Monitor cruise control OFF signal voltage at the ECM connector while pressing the OFF button. The voltage should transition cleanly between states. No change or erratic signal confirms the circuit fault.
3
Step 3: Disconnect the switch and measure contact resistance. The switch should show near 0 ohms when pressed and open circuit when released (or the inverse, depending on design). Replace if contacts are worn.
4
Step 4: Test continuity from the switch connector through the clock spring to the ECM connector on the OFF signal wire. Rotate the steering wheel during the test to check for clock spring intermittents.
5
Step 5: If the switch and wiring test good, verify the ECM is receiving a valid signal by applying the expected voltage directly to the ECM input pin. If the ECM does not respond, it may have an internal input circuit fault.
Estimated Repair Cost
$40 - $350
Parts + labor, varies by vehicle and location
The ECM has detected a malfunction in the cruise control OFF signal circuit. The system is not receiving a valid OFF/cancel signal from the cruise control switches when the driver attempts to deactivate cruise control. This could mean the OFF switch is stuck, the signal wire is open, or the ECM is n...
The most common cause of P0566 (Cruise Control Off Signal Malfunction) is: Faulty cruise control OFF/cancel switch with stuck or worn contacts that do not produce a valid OFF signal
Typical repair costs for P0566 range from $40 to $350, depending on the vehicle, location, and whether you do it yourself or go to a shop.
While the cruise control OFF switch may not function, the brake pedal and clutch pedal (manual transmission) always serve as backup cruise cancel methods. However, the driver should be aware they must use the brake to cancel cruise until this fault is repaired.
Start by connecting an OBD2 scanner to read the code and any freeze frame data. Then follow the diagnostic steps specific to P0566 to identify the root cause.
OBDHut Mobile App
Scan codes directly from your car with the OBDHut app.
Coming Soon
Quick Info
Category
Powertrain
System
Cruise Control System
Difficulty
Type
Generic (SAE)
Recommended Tools
OBD2 Scanner
A quality scan tool helps you read codes, view live data, and clear faults.
