P0782 is a generic OBD-II trouble code indicating that the powertrain control module (PCM) or transmission control module (TCM) has detected a malfunction during the 2‑3 upshift. The code is set when the transmission fails to complete the shift from second gear to third gear within the expected parameters, often due to hydraulic or mechanical issues in the transmission.
The solenoid that controls the 2‑3 shift may be stuck, open, or shorted, preventing the proper hydraulic command needed for the upshift.
Insufficient or dirty fluid reduces hydraulic pressure and can cause the valve body or clutch to malfunction during the shift.
The hydraulic passages that route fluid for the 2‑3 shift may be clogged or stuck, leading to an incomplete shift.
Worn clutch plates, band, or other internal parts can prevent the 2‑3 gear from engaging properly.
An open circuit, short, or poor connection can prevent the solenoid from receiving the correct signal from the TCM/PCM.
A failed or mis‑programmed control module can cause incorrect shift commands, although this is a relatively rare cause compared to the above items.
Yes. Many technicians and DIYers are quick to replace the control module, but the PCM/TCM is rarely at fault; the problem is usually the solenoid, fluid, or valve body.
While the vehicle may still move, the transmission may slip, shift harshly, or go into limp mode. Driving in this condition risks further damage and should be addressed promptly.
If the code is triggered by low or contaminated fluid, a fluid replacement can restore proper hydraulic operation and may clear the code. However, if the solenoid or internal components are faulty, a fluid change alone will not fix the issue.
Testing the solenoid’s resistance (comparing to factory specs) and verifying that it clicks or actuates when powered usually reveals a failure. An inline pressure test can also confirm whether the solenoid is delivering the correct hydraulic pressure for the shift.