OBD-II Generic Error Code P0590: How to Fix It

Q: Can I drive with error code P0590?

Yes, you can drive the vehicle, but the cruise control may not function. It's safe to drive short distances, but have the issue diagnosed soon.

Q: Will disconnecting the battery clear code P0590?

Disconnecting the battery may temporarily clear the code, but it will return if the problem isn't fixed. It's better to use an OBD2 scanner to clear the code after repairs.

Q: What does cruise control multifunction input B mean?

Multifunction input B refers to a specific signal line used by the cruise control system, typically from the brake switch or clutch switch. A stuck signal means the PCM sees a constant voltage when it should change.

Q: How much does it cost to fix code P0590?

Cost varies by cause. A brake light switch can cost $15-$50; a cruise control switch $50-$150; labor adds $50-$150. DIY can save labor costs.

Q: What tools do I need to diagnose P0590?

You'll need an OBD2 scanner to read and clear codes, and a multimeter to test switch continuity and wiring. Basic hand tools may be needed for switch replacement.

Abstract

OBD-II error code P0590 indicates a problem with the cruise control system: the multifunction input B signal is stuck. This means the signal from the brake pedal switch, clutch switch (manual), or other input to the powertrain control module (PCM) is not changing as expected. While you can still drive the car, cruise control may be disabled. This guide walks you through common causes and fixes.