Cruise Control Multi-Function Input "B" Circuit Low
Code P0592 indicates the cruise control multifunction input B circuit is detecting a low voltage condition. This circuit monitors steering wheel cruise control buttons and related inputs; and a low voltage reading prevents the cruise control system from functioning properly.
What You Might Notice
- Cruise control inoperative or won't engage
- Cruise control light illuminated on dashboard
- Unable to set or maintain desired cruise control speed
- Abnormal vehicle speeds when cruise control is active
- Cruise control buttons unresponsive to input
Most Common Causes
- 1
Faulty cruise control switch or button
The multifunction steering wheel buttons for cruise control are worn, damaged, or producing incorrect voltage signals to the control module.
- 2
Wiring harness or connector issues
Corroded, loose, or damaged wiring and connectors in the cruise control circuit are causing voltage drops or signal loss.
- 3
Cruise control module malfunction
The cruise control or body control module has an internal fault preventing proper signal processing of the multifunction input.
- 4
Steering wheel contact ring failure
The slip ring or contact assembly that connects steering wheel buttons to the vehicle harness is worn or failing, breaking the electrical connection.
How to Diagnose It
- 1
Check Faulty cruise control switch or button — The multifunction steering wheel buttons for cruise control are worn, damaged, or producing incorrect voltage signals to the control module.
- 2
Check Wiring harness or connector issues — Corroded, loose, or damaged wiring and connectors in the cruise control circuit are causing voltage drops or signal loss.
- 3
Check Cruise control module malfunction — The cruise control or body control module has an internal fault preventing proper signal processing of the multifunction input.
- 4
Check Steering wheel contact ring failure — The slip ring or contact assembly that connects steering wheel buttons to the vehicle harness is worn or failing, breaking the electrical connection.
How to Fix It
- 1
Inspect and clean connectors
Locate the cruise control module and steering wheel switch connectors. Clean any corrosion from terminals and ensure connectors are fully seated and locked.
- 2
Test cruise control switch voltage
Use a multimeter to check the voltage at the multifunction switch connector when buttons are pressed. Compare against manufacturer specifications to identify if the switch is faulty.
- 3
Replace multifunction steering wheel switch
If voltage testing confirms the switch is defective, remove the steering wheel airbag cover and replace the cruise control switch assembly with an OEM or quality replacement.
- 4
Repair or replace wiring harness
If connectors and switch test good, inspect the wiring harness between the steering wheel and cruise control module for breaks or corrosion. Repair damaged wires or replace the harness section.
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