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. P056C concerns the cancel button, which interrupts control but keeps the set speed – unlike the off signal P0566. GM (from about 2015) sets it when the button is reported pressed for over 20 s. Older code lists still show it as reserved.
Low severity. Can I keep driving?You can keep driving, but check that the brake lights work: that part is a safety issue.
Symptoms
- Cruise control cannot be engaged or cancels immediately
- Cruise control locked out
- No check engine light, engine runs normally
Most likely causes
- Cancel 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
What to check, in order
Start with the simplest. You can tick off each step.
Good to know
- Repair difficulty: medium
What each character of P056C means
- P: Powertrain: engine and transmission
- 0: Generic code: same on every make
- 5: Speed and idle
- 6C: Specific fault in that system
Frequently asked questions
Can I keep driving with code P056C?
You can keep driving, but check that the brake lights work: that part is a safety issue.
What causes code P056C?
The most common causes are: cancel button stuck or faulty; moisture or wear in the steering wheel switch; contact resistance in clockspring or steering wheel connector.
Related codes
- P0566Cruise Control Off Signal
- P0565Cruise Control On Signal
- P0567Cruise Control Resume Signal
- P0568Cruise Control Set Signal
- P0571Brake Switch A Circuit
Sources
- gsi.ext.gm.com: 18OBDG03A Engine Diagnostics
- saabwisonline.com: dtc p0564 p0567 or p0568
- law.cornell.edu: 13 CCR 1968.2
Values and procedures vary by manufacturer. If it affects brakes, steering, fuel or high voltage, see a professional. Updated: 2026-11-04. How we build these pages.