Powertrain, generic · Vehicle speed, idle control and auxiliary inputs

P0566 Cruise Control Off Signal

Check engine lightUsually off
EmissionsNot relevant
Drive cycleNot required
Limp modeNo

Cruise control buttons are almost always a resistor ladder on one or two signal lines, each button giving its own voltage; the module reading it (GM and Saab from about 2010: the body module; FCA: steering column module or PCM) sends the button state to the engine module over CAN. CARB names cruise control as the example of an emission-neutral diagnosis – it is simply switched off – so GM lists all these codes as type C and Ford as non-MIL: no warning lamp, the engine runs normally. P0566 concerns the off signal of the main switch – implausible, stuck or invalid. No manufacturer document available to us uses this code. GM reports the on/off button under P0565 and the cancel button under P056C.

Likely causes

On/off button stuck or faulty
Moisture or wear in the steering wheel switch
Contact resistance in clockspring or steering wheel connector
Body module or cruise module

Symptoms

  • Cruise control cannot be switched on or off
  • Cruise control locked out
  • No check engine light, engine runs normally

Repair estimate

DifficultyMediumDIY possible
Parts and labour€40–400
Time0.5–2 h

Typical range across vehicles; the real cost depends on what the testing finds.

Parts involved

cruise control switchclockspringswitch wiringbody control module

Related codes

P0565P056CP0564P0567P0568

References: law.cornell.edu, saabwisonline.com.