P0790: Normal/Performance Switch Circuit
What to do
The car drives normally in its default shift programme; only the sport or economy button has stopped working. Nothing about this fault threatens the transmission, and it can wait for a convenient moment.
What this code means
A circuit fault in the switch that selects between shift programmes — the sport, comfort or economy button, depending on the vehicle. It is worth stating plainly what this does and does not mean, because it sits in a block full of serious codes and is not one of them.
The switch chooses which map the transmission shifts to. Nothing about the transmission's ability to shift depends on it, and when the module cannot read the switch it simply uses the normal programme. So the fault is that a preference cannot be expressed, not that anything is wrong with the gearbox. The vehicle drives entirely normally, in the setting most people leave it in anyway.
These are ordinary dashboard switches on ordinary interior wiring, which puts them within reach of a straightforward electrical repair rather than anything involving the transmission.
Likely causes
Start here
- Faulty transmission mode switch · easy
- Corroded or loose connector · easy
Less common
- Open circuit in switch wiring · moderate
Rare
- Faulty transmission control module · specialist
Symptoms
Components involved
Information, not instruction
CarGeek is a reference, not a service manual. Its pages are written from public sources and from what other people have found, never from a manufacturer's own service information, so they can be wrong or incomplete for your particular vehicle. Some of what they describe carries real risk: high voltage, fuel under pressure, stored energy, hot and moving parts.
Have anything you intend to act on checked by a trained person against the manufacturer's own procedure for your vehicle. Nothing here replaces that procedure.
Community experience
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What makes one worth reading:
- The car — make, model, year and engine. The same fault behaves differently on each.
- What you measured, not only what you replaced.
- What actually fixed it — or that nothing did, which is worth knowing too.
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