Cruise Control Multi-Function Input "B" Circuit
P0589 indicates a fault in the cruise control multifunction input B circuit, which prevents the vehicle's cruise control system from operating properly. This circuit detects input signals from cruise control switches and when it fails, the system cannot engage or maintain set speeds.
What You Might Notice
- Cruise control will not activate or engage
- Cruise control light remains illuminated constantly
- Unable to set or adjust cruise control speed
- Vehicle maintains inconsistent speeds when cruise control is attempted
- Cruise control buttons unresponsive to input
Most Common Causes
- 1
Faulty cruise control switch
The multifunction input B switch on the steering wheel may be defective or worn, preventing proper signal transmission to the control module.
- 2
Wiring harness damage or corrosion
The electrical circuit connecting the cruise control switch to the PCM may have broken, shorted, or corroded connections.
- 3
PCM or control module malfunction
The powertrain control module may have failed to properly receive or interpret signals from the cruise control input circuit.
- 4
Steering wheel connector issues
The connector at the steering wheel column connecting the cruise control switches may be loose, damaged, or corroded.
How to Diagnose It
- 1
Check Faulty cruise control switch — The multifunction input B switch on the steering wheel may be defective or worn, preventing proper signal transmission to the control module.
- 2
Check Wiring harness damage or corrosion — The electrical circuit connecting the cruise control switch to the PCM may have broken, shorted, or corroded connections.
- 3
Check PCM or control module malfunction — The powertrain control module may have failed to properly receive or interpret signals from the cruise control input circuit.
- 4
Check Steering wheel connector issues — The connector at the steering wheel column connecting the cruise control switches may be loose, damaged, or corroded.
How to Fix It
- 1
Inspect and test cruise control switch assembly
Use a multimeter to test the cruise control switch for continuity and proper resistance values. Replace the switch assembly if it fails testing.
- 2
Check wiring harness and connectors
Visually inspect the cruise control circuit wiring from the steering wheel to the PCM for damage, corrosion, or loose connections. Repair or replace damaged wiring and clean corroded connectors.
- 3
Test and reprogram PCM if needed
Have the PCM tested with a professional diagnostic scanner to verify it is receiving signals correctly. Update or reprogram the module if necessary.
- 4
Replace PCM as last resort
If all wiring and switches test good but the code persists, the powertrain control module may need replacement and reprogramming.
Need a deeper diagnosis?
Search for related repair guides or browse by system.