my 05 cavalier is shifting funny and throwing a check engine light. also my driving lights come on while in park and neutral. it has been raining hard and I drove through a lot of puddles. I was told to check for wet sensors but I don't know where they are. and then I was told that if that didn't fix it to check all ground wires but I don't know where they are either. I tried to dry out the engine with warm air, but to no avail. this is my first time doing anything like this and I have no idea what I'm doing.

 

jaado1992 Welcome to the forum...

Its very possible that a wiring harness and connectors have gotten wet, unfortunately those wires and connectors are most likely on the underside of the vehicle.... (think like water) I would suggest getting it up on jack stands so that you can get under the vehicle safely and inspect for those areas that water can get at when splashed... given the age of your vehicle some of the protective wire loom and tape may have come loose and allowed water to more easily get into places....

 

There is a sensor on the back of the transaxles near your exhaust manifold. It is on the top where the axle goes into the transmission. (pass. Axle) I would check this sensor.

 

the vehicle speed sensor and map sensor are 2 inputs that the trans will use to control shift points. Get the dtc read and post it here. This will give you a starting point to begin diagnosis.

for the lighting problem; is the car equipped with daytime running lights.

 

we decided to check fuses before tearing into anything serious. there was a 10A fuse with a short in it. after replacing it, it was back to normal. the fuse was for the engine relays. thanks for your help though!

 

this was the sensor that was throwing the codes for the check engine light when we hooked it up to a code reader. but after changing out the fuse, we had no problems.

 

Thanks for the follow up, glad to hear it was a simple fix of a fuse