P0790Generic code

P0790 Code: Normal/Performance Switch Circuit

The P0790 code means there is a fault in the switch that selects the shift mode (normal, sport or economy). The transmission usually stays in normal mode. It is a minor problem that is cheap to fix and safe to drive with.

Severity
Low
Can I keep driving?
Yes, no immediate risk
Estimated cost
$20 to $200
Difficulty
Easy
System
Transmission
Applies to
All OBD2 vehicles

Updated Reviewed by Renzo Chacca

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What the P0790 code means

Some vehicles let you choose a shift mode with a button. The computer reads the switch and changes the shift strategy to match. If the signal is not valid, it stores the P0790 code and falls back to normal mode.

The cause is usually the button itself or its connector.

If the switch is in the console, spilled liquids are a frequent cause: clean the button or replace it. On some vehicles the shift mode is selected from the screen, and the code then points to a communication fault with the module that manages it.

P0790 code symptoms

  • The sport or economy mode does not work.
  • Check engine light on.

Likely causes of the P0790 code

  1. Faulty button or switch from wear or dirt.
  2. Connector or wiring that is damaged or corroded.

How to diagnose the P0790 code step by step

  1. Watch the button state on the scan tool while you press it.

How to fix the P0790 code

  • Replace the switch or repair the wiring.

Technical reference data

  • Switch with 2 or 3 wires.
  • These are approximate values: check the manufacturer data for your vehicle.

Brand-specific notes

This code appears on Mazda, Hyundai and Kia vehicles.

P0790 on Mazda, Hyundai and Kia

On these makes the code usually comes down to the mode button or its connector, so start there before you look at anything else in the transmission.

Frequently asked questions about P0790

What does the P0790 code mean?
It is a generic OBD2 code that means there is a fault in the circuit of the switch that selects the shift mode. The computer does not get a valid signal from the button, so it uses normal mode.
Can I drive with a P0790 code?
Yes. With a P0790 code the transmission keeps working in normal mode, and you only lose the sport or economy setting.
Does it affect the transmission?
Only the shift mode. The transmission itself is not damaged by this code.
Is it expensive to fix?
No. It is usually a switch or a connector, which is a cheap repair.
How much does it cost to fix P0790?
Between $20 and $200.
Will a P0790 code clear itself?
If the button was only dirty or the connection was loose, it can go out for a while. A worn or damaged switch will bring the code back.
What is the most common cause of P0790?
The mode button itself or its connector, often after liquid was spilled on the console. Cleaning or replacing the switch usually solves it.

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