Hi fellas,
My 98 EL Fairmont has been staring in and holding 3rd (or Limp Home Mode) recently. It will usually go back to normal if I turn off the car completely then turn it on and wait for the airbag light to go off, but yesterday I put a new battery in it and it held 3rd regardless of restarting it, I pulled the neg terminal off and reset the ECU because my mechanic (the old man) thinks it's a voltage problem but it still didn't shift. Having said that, we left it overnight then drove it this morning and it shifted fine.
If anyone has any experience or advice on this to point us one the right direction that would be great

Cheers