OBD-II Generic Error Code P0790: How to Fix It

Q: Can I drive with code P0790?

You can drive short distances, but the transmission may not shift correctly. Prolonged driving can cause further damage. It's best to diagnose and fix the issue promptly.

Q: What does 'Normal/Performance Switch Circuit' mean?

This switch tells the transmission control module (TCM) whether you want normal or sporty shifting. A circuit fault means the TCM can't read the switch position, leading to limp mode or improper shifting.

Q: How much does it cost to fix P0790?

If it's just a faulty switch, the part costs $20-$50 and DIY labor is free. If wiring repair is needed, costs vary. A mechanic may charge $100-$200 for diagnosis and repair.

Q: Will a bad battery or alternator cause P0790?

It's unlikely. Low voltage can cause multiple random codes, but P0790 specifically points to the switch circuit. However, ensure battery voltage is above 12.6V to rule out electrical issues.

Q: How do I find the normal/performance switch on my car?

Check the center console near the gear shifter, often labeled 'Normal' and 'Sport' or with an icon. Some vehicles have it on the dashboard. Consult your owner's manual.

Abstract

Error code P0790 indicates a problem with the normal/performance switch circuit in your vehicle's transmission. This switch allows you to select between normal and performance driving modes, and when it malfunctions, you may experience shifting issues or the check engine light may come on. This guide will help you diagnose and fix the problem.