Hello and thanks for the donation!
Did you have any repairs made recently before the engine light started showing the DTC P1633?
This code sets when either there is corrosion on the battery terminals / cables or if there is a problem with a wiring harness. The code also sets if the vehicle's powertrain control module (PCM) is failing.
I suggest having the trouble code deleted. If it comes back and the battery cables and terminals are clean and tight, the PCM is the culprit.
Tuesday, July 21st, 2009 AT 9:48 PM