P056B code meaning
Cruise Control Decrease Distance Signal
What P056B means
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. P056B exists only with adaptive cruise control: the button to decrease following distance is stuck or invalid; counterpart of P056A. FCA's switch reads the distance button over the same ladder as the others. No manufacturer document available to us uses this code.
P056B at a glance
- Check engine lightUsually not
- Emissions testNot an emissions code
- Limp modeNot expected
- Repair difficultyMedium, DIY possible
- Typical labor0.5 to 2 hours
- Clears after repairWhen cleared with a scanner
Symptoms of P056B
- Following distance cannot be decreased
- Cruise control locked out
- No check engine light, engine runs normally
Common causes of P056B
- Most likelyDistance button stuck or faulty
- PossibleMoisture or wear in the steering wheel switch
- PossibleContact resistance in clockspring or steering wheel connector
- Less likelyBody module or cruise module
Check the most likely causes first. Replacing parts by guesswork is the most expensive way to clear a code.
Parts involved
Cruise control switchClockspringSwitch wiringBody control module
What each part of P056B means
| P | Powertrain system: engine, fuel system, ignition, emissions and transmission. |
| 0 | Generic code: it means the same on every make (SAE standard). |
| 5 | Area: vehicle speed, idle control and auxiliary inputs. |
| 6B | The exact fault in that area. |
What to do next
- Note P056B and any other codes stored with it: several codes together often point to one cause.
- Check for loose connectors and damaged wiring around the parts the code names.
- Check open recalls for your car: some faults are fixed for free by the dealer. Enter your VIN.
- Clear the code only after the repair. If it comes back, the fault is still there.
Buying a used car? Scan it for stored codes before you pay. A recently cleared memory can hide a problem.
Questions about P056B
What does P056B mean?
P056B means "Cruise Control Decrease Distance Signal". 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. It is a generic code, so it means the same on every make.
Is it safe to drive with P056B?
P056B does not normally turn on the check engine light by itself. Watch for the symptoms above and have it checked soon.
Will P056B fail an emissions test?
P056B is not an emissions code, so on its own it usually does not fail an emissions test. Other stored codes or a lit check engine light still can.
How hard is P056B to fix?
Difficulty: medium. A typical repair takes 0.5 to 2 hours of work. A careful DIY repair is possible with basic tools and a scanner.
Will P056B clear itself after the repair?
Clear the code with a scanner after the repair. If the fault is fixed, it does not come back.