Faulty or worn distance decrease button or switch on the steering wheel or stalk (stuck or intermittent contacts); Wiring damage, corrosion or poor connections in the switch circuit or its connector; Fault in the steering wheel clock spring or rotary connection carrying the switch signal; Moisture or spilled liquid contamination in the switch assembly; Fault in the control module that reads the switch, such as the cruise, radar or body control unit; Outdated or faulty module software, only where the manufacturer lists it as a known cause.

P056B

Cruise Control Decrease Distance Signal.

Generic
Powertrain
Generic code
Low severity

How this code is built

P: SystemPowertrain
0: Defined bySAE, the same on every car
5: AreaVehicle speed, idle control and auxiliary inputs
6B: FaultThe specific fault in that area

What it means

P056B relates to the Cruise Control Decrease Distance Signal, the input used on adaptive or distance-keeping cruise control to shorten the following gap. The control unit has seen a fault with this signal, such as an implausible, stuck, missing or out-of-range input from the switch or its circuit. The exact trigger conditions and which module sets the code depend on the vehicle.

Symptoms

Cruise control warning light or message on the dash
Adaptive cruise control unavailable or will not engage
Following distance cannot be reduced using the steering wheel or stalk button
Distance setting changes by itself or appears stuck
Other cruise functions such as set, resume or cancel behaving oddly
Engine warning light on in some cases

Possible causes

Faulty or worn distance decrease button or switch on the steering wheel or stalk (stuck or intermittent contacts)likely
Wiring damage, corrosion or poor connections in the switch circuit or its connectorlikely
Fault in the steering wheel clock spring or rotary connection carrying the switch signalpossible
Moisture or spilled liquid contamination in the switch assemblypossible
Fault in the control module that reads the switch, such as the cruise, radar or body control unitrare
Outdated or faulty module software, only where the manufacturer lists it as a known causerare

How to diagnose

Read all stored and pending codes and note the freeze frame data, then check for other cruise, radar or steering wheel switch codes
Check for any technical service information for the model covering this code and its trigger conditions
Operate each cruise and distance button and watch live data, if available, to see whether the decrease distance input responds cleanly and returns to idle
Inspect the switch, its connector and the wiring visible near the steering column for damage, corrosion, moisture or pin tension problems
Check the other buttons on the same switch pad for faults, since a shared circuit points to the switch or clock spring
Test the circuit for supply, signal, earth, continuity and resistance against the manufacturer's specification, flexing the harness to find intermittent faults
Check the clock spring or rotary connector for continuity and signal dropouts while turning the wheel
Clear the code and road test to confirm whether it returns, and check module software status if no physical fault is found

How to fix

Replace the faulty distance decrease switch or the complete switch assembly
Repair or replace damaged wiring and clean or replace corroded connectors
Replace the clock spring or rotary connector if it is faulty
Dry out and clean contaminated switch components where possible, or replace them if damage remains
Update or reprogram the control module software only if the manufacturer identifies this as a cause
Replace or repair the control module only after the switch and wiring have been proven good

Can I keep driving?

Low severity

The car is normally safe to drive, as the fault mainly affects cruise control convenience features. Avoid relying on adaptive cruise until it is repaired and book it in at your convenience.

Guide written by AI from the code's definition. Confirm with a diagnosis before replacing parts.