What Does P0790 Mean?
The normal/performance switch circuit is malfunctioning. This switch allows the driver to toggle between normal and performance (sport) transmission shift modes. The TCM has detected an electrical fault in the switch circuit — either an open, short, or implausible signal. The transmission may default to normal shift mode and the sport/performance mode button will not function.
Common Causes
35%
Faulty normal/performance mode switch (internal contact failure)
25%
Wiring fault in switch-to-TCM circuit (open or short)
20%
Corroded or loose connector at switch or TCM
12%
TCM input circuit failure for mode switch signal
8%
Ground circuit issue for the mode switch
Diagnostic Steps
1
Monitor the normal/performance switch PID in live data while toggling the switch — verify the TCM sees the state change.
2
Check for 12V power and ground at the mode switch connector with the ignition on.
3
Measure resistance through the switch in both positions to confirm proper contact closure.
4
Inspect the wiring between the switch and the TCM for opens, shorts, or damaged insulation.
5
If the switch and wiring are good, check the TCM connector pins for corrosion or backed-out terminals.
Estimated Repair Cost
$75 - $400
Parts + labor, varies by vehicle and location
The normal/performance switch circuit is malfunctioning. This switch allows the driver to toggle between normal and performance (sport) transmission shift modes. The TCM has detected an electrical fault in the switch circuit — either an open, short, or implausible signal. The transmission may defaul...
The most common cause of P0790 (Normal/Performance Switch Circuit Malfunction) is: Faulty normal/performance mode switch (internal contact failure)
Typical repair costs for P0790 range from $75 to $400, depending on the vehicle, location, and whether you do it yourself or go to a shop.
Safe to drive. The transmission will default to normal shift mode. You will lose the ability to select sport/performance mode, but all other transmission functions remain operational. This is a convenience feature issue, not a safety concern.
Start by connecting an OBD2 scanner to read the code and any freeze frame data. Then follow the diagnostic steps specific to P0790 to identify the root cause.
OBDHut Mobile App
Scan codes directly from your car with the OBDHut app.
Coming Soon
Quick Info
Category
Powertrain
System
Automatic Transmission
Difficulty
Type
Generic (SAE)
Recommended Tools
OBD2 Scanner
A quality scan tool helps you read codes, view live data, and clear faults.
