Worn, dirty or faulty cruise control switch or steering wheel control stalk; Damaged, chafed or corroded wiring or connector in the switch circuit; Faulty clock spring (spiral cable) in the steering wheel on models where the switches pass through it; Brake or clutch pedal switch fault affecting the cruise control logic on some models; Poor earth or supply voltage to the switch circuit; Fault inside the control unit or a software issue where a known calibration update exists.

P0589

Cruise Control Multi-Function Input B Circuit.

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
89: FaultThe specific fault in that area

What it means

P0589 is the SAE J2012 generic code for a fault in the Cruise Control Multi-Function Input B circuit. The engine or powertrain control unit monitors the signal from the cruise control switch or switches and sets the code when the voltage or signal pattern is outside the expected range or does not match the driver's action. The exact switch layout and what 'input B' refers to vary by manufacturer and model.

Symptoms

Cruise control will not set, resume or cancel
Cruise control cuts out unexpectedly
Cruise control warning light or message on the dash
Steering wheel cruise buttons unresponsive or intermittent
Engine management light on in some vehicles

Possible causes

Worn, dirty or faulty cruise control switch or steering wheel control stalklikely
Damaged, chafed or corroded wiring or connector in the switch circuitlikely
Faulty clock spring (spiral cable) in the steering wheel on models where the switches pass through itpossible
Brake or clutch pedal switch fault affecting the cruise control logic on some modelspossible
Poor earth or supply voltage to the switch circuitpossible
Fault inside the control unit or a software issue where a known calibration update existsrare

How to diagnose

Read all stored codes and freeze frame data, noting any other cruise, brake switch or steering column codes
Test the cruise control functions (set, resume, accelerate, decelerate, cancel) and note which buttons fail
Visually inspect the switch, stalk and connectors for damage, moisture, corrosion or loose pins
Check the brake and clutch pedal switch operation and adjustment, as these can affect cruise logic
Using the manufacturer wiring diagram, check the switch circuit for supply, signal and earth, and for shorts or open circuit
Measure switch signal voltage or resistance in each button position and compare with the model specification
Wiggle-test the wiring and steering wheel connections while monitoring live data for dropouts
Check for relevant software updates or technical bulletins for the model before suspecting the control unit

How to fix

Replace the faulty cruise control switch or steering wheel control assembly
Repair or replace damaged wiring and clean or replace corroded connectors
Replace the clock spring if testing shows it is the cause of the signal fault
Replace or readjust a faulty brake or clutch pedal switch
Restore a good supply or earth connection to the circuit
Update the control unit software only where a published fix exists for this fault, or replace the unit if confirmed faulty

Can I keep driving?

Low severity

The car is generally safe to drive as only the cruise control is affected. Book it in at your convenience, and have it checked sooner if the brake lights or other functions also act oddly.

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