The hold light and check engine light mean that the vehicle computer has sensed a problem with the transmission. This can be related to a sensor, slippage, or one of the electronic control devices that operate the transmission. You will need to scan the system and then perform the listed diagnosis for whichever code or codes have been set. You can have the system scanned at many auto parts stores. The code should stay in the computer for at least 50 starts even if it only sets intermittently.

The park/neutral switch could actually be the cause, the computer needs to see that the transmission is in the proper gear range and it uses the Park/neutral switch for this information. If you can get the codes by having the vehicle scanned at the parts store, I can give a more specific recommendation as to which part is bad.

and finally An error has occurred in the transmission control system. You need a scan tool to retrieve the trouble code to proceed with diagnostics and rectification.