How serious is the code?
Having a P0826 diagnostic code doesn’t mean your vehicle is about to leave you stranded. However, you likely won’t be able to manually control the transmission.
Symptoms
Symptoms of a P0826 include:
Harsh shifting
Manual shift function disabled
Limp mode
Causes
Damaged wiring or connectors
Damaged or faulty up and down shift switch
How to diagnose the code?
It’s not uncommon for electrical issues to cause a P0826 OBDII trouble code, so wiring and connectors should be carefully inspected for any signs of damage. If no issues are detected, the up/down shift switch will need to be tested.