The P0790 trouble code indicates a malfunction in the Normal or Performance Switch circuit.
P0790 Normal/Performance Switch Circuit Malfunction
Code symptoms P0790.
1. Check Engine Light (CEL) illuminated on the dashboard.
2. Issues with switching between normal and performance driving modes (if applicable).
3. Decreased performance or drivability.
4. Transmission may not respond properly to driver inputs.
5. Other related trouble codes may be present.
This code is common in brands such as:: Chevrolet, Renault, Ford, Toyota, Nissan, Mercedes Benz, Honda.
Causes of the code P0790.
1. Faulty Normal or Performance Switch.
2. Wiring issues, such as damaged wires or poor connections in the circuit.
3. Defective transmission control module (TCM).
4. Software issues with the TCM.
5. Faulty vehicle speed sensor.
Code Solutions P0790.
1. Begin by using a scan tool to retrieve freeze frame data and any other stored trouble codes. This information can provide insight into when and how the malfunction occurred.
2. Inspect the wiring and connectors associated with the Normal or Performance Switch circuit for any signs of damage, corrosion, or loose connections. Repair or replace any damaged wiring or connectors as needed.
3. Test the Normal or Performance Switch itself using a multimeter or other appropriate diagnostic tools to ensure it is functioning properly. Replace the switch if necessary.
4. Check the vehicle speed sensor to ensure it is operating correctly. A malfunctioning speed sensor can affect the operation of the transmission.
5. If the above steps do not resolve the issue, perform further diagnostics on the transmission control module (TCM) and related systems to identify any faults or software issues.
6. Clear the trouble codes from the vehicle’s computer memory and test drive the vehicle to see if the code returns. If it does, further diagnosis may be necessary.