P0590
Cruise Control Multi-Function Input B Circuit Stuck
Cruise / speed control
Generic OBD-II
Low
What it means
P0590 sets when the cruise control multi-function input 'B' circuit appears stuck, so the ECM sees an implausible or unchanging switch signal. Cruise control may be unresponsive or refuse to set a speed. It's a convenience-system electrical fault and doesn't affect how the engine runs.
Low
Can I keep driving? Fine to drive — only cruise control is affected; the engine and normal driving are unchanged.
Common symptoms
What you'll notice
- Cruise control unresponsive or won't set a speed
- Cruise control switches appear stuck or don't register
- Cruise control indicator light on
- Check-engine light on (on some vehicles)
Common causes
Most likely first
- Failed cruise control multi-function switch (stuck contact)Likely
- Corroded or damaged electrical connections in the switch circuitCommon
- Failed cruise control moduleCommon
- Failed powertrain control module (PCM)Less often
How to diagnose & fix
Work through it in order
- Operate the cruise control buttons and watch the switch signal on a scan tool for a stuck value.
- Inspect the switch connector and wiring for corrosion or damage; clean or repair as needed.
- Replace the cruise control multi-function switch if a contact is stuck.
- If the switch and wiring are good, test the cruise control module or PCM. Clear and re-test after each step.
FAQ
Quick answers
Is it safe to drive with P0590?+
Yes. Only cruise control is affected — the engine and all primary driving controls work normally.
Can I just clear P0590?+
It will come back if a switch contact is genuinely stuck. The fault needs to be repaired for cruise control to work again.
Related codes
Often seen with P0590
Read & clear P0590 yourself
Scan your car, confirm the code, and clear it once it's fixed — with OBD DashX on your phone.
✓ Verified name — SAE J2012 / ISO 15031-6Guidance reviewed by OBD DashX