2001 Pontiac Montana, 160,000

on summer vacation, over 900 miles from home, trans will not shift pass 3rd. No codes show, disconnected battery to reset computer, still will not shift & no codes

It’s in the ‘limp mode’ to protect the tranny from being burned out.

Still. it will let you ‘limp’ to a tranny repair shop.

You can’t fix it on the street as a scanner has to be hooked up and the vehicle driven to assess the problem.

Low automatic transmission fluid level? Some cars you check the level with the engine running in Park. Some, with the engine off. Read the dipstick.