Service engine soon light after hitch wiring (fixed)
As some of you know, I had a trailer hitch installed on my 2005 GXP along with wiring for the lights. Service engine light came on the next day, and a GM Tech2 scanner won't communicate with the car. The tech at the dealership where I work thinks there'* a faulty connection somewhere that won't allow the scanner to communicate with the car. I know next to nothing about wiring, and have no idea what to look for when I pull it apart. I've checked the hot wire connection at the battery and taped up the connector block that was just flopping around loose under the seat. The other connections are at the left taillight and I haven't had a chance to pull it apart and check for anything obvious. Any thoughts would be greatly appreciated.
Oh, and if this weren't enough, when the hitch was installed, the exhaust had to be dropped at the rear to replace and reposition the hangers and during this process pulled the O2 sensor out from under the heat shield and the shield had cut the wires to the sensor and the heat shield was rubbing against the O2 sensor, making the most god awful noise you can imagine. $140 later, it was fixed at the dealership and the bill sent to the installer, who is making good on it.
I know I should just take it back to the installer and have him figure out where the fault is, but I'm just really not sure I trust him to be working on my car anymore at this point. Thanks.