What are the common causes of P0790?

A faulty normal/performance switch. An open or short in the switch wiring. Corrosion at the transmission connector. Low battery voltage disturbing the PCM. A PCM or TCM fault on the switch input.

Read the normal/performance switch state on a scan tool. Test the switch circuit for an open or short. Measure switch resistance in each mode. Check the battery voltage and ground. Replace the switch if the circuit tests good. Clear the code and retest.

P0790

Normal/Performance Switch Circuit

System: Transmission (P code)
Lamp: Check Engine Light
Category: Powertrain - Transmission

What it means

P0790 means Normal/Performance Switch Circuit.

Where it lives

For P0790, the part to look at first is the switch named here.

Check these first

A faulty normal/performance switch
An open or short in the switch wiring
Corrosion at the transmission connector
Low battery voltage disturbing the PCM
A PCM or TCM fault on the switch input

What to do next

Read the normal/performance switch state on a scan tool
Test the switch circuit for an open or short
Measure switch resistance in each mode
Check the battery voltage and ground
Replace the switch if the circuit tests good
Clear the code and retest

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Updated

Generic SAE J2012 definition. Last updated 2026-10-10.