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

P0577 Cruise Control Input Circuit High

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. P0577 means the input signal is above its upper limit – an open signal or switch ground (often in the clockspring) or a short to positive. FCA's ladder treats over 4.706 V as circuit high, with about 4.54 V at rest. No manufacturer document available to us uses this code. For line A makers use P0581.

Likely causes

Signal or switch ground open (clockspring)
Signal shorted to positive
Module faulty

Symptoms

  • Cruise control inoperative
  • Cruise control locked out
  • No check engine light, engine runs normally

Repair estimate

DifficultyMediumDIY possible
Parts and labour€40–450
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

P0575P0576P0581P0564

References: law.cornell.edu, static.nhtsa.gov.