Hey guys, so in my other thread we found out that a faulty DRL module was causing my car to go into limp mode. It's a 2003 sedan. All was fine for 2 days and I've been driving with the AC and heater off. Yesterday I turned on the AC in auto/econ mode and after a while my car goes into limp mode again. I quickly check the DRLs and they're not on. I pop the hood and feel the module and it's so hot that I can barely touch it. Same with the reservoir next to it. I shut the car off and turn it back on, all the lights are on (battery, brake, vdc,slip, but no CEL). At idle the DRLs are on but if you rev it a bit, the DRLs shut down.

After letting the car cool down overnight, it seems to be working fine today. I drove around and tested it, I cranked the interior temp to 32C and put it on full blast. Drove around for about 15 minutes and when I got back home I popped the hood and felt the module and it was only warm. My question is, can the auto/econ mode make the engine bay so hot that it overheated the DRL module or is it likely cause by a short somewhere along the wires. I was thinking of maybe wrapping the module in the same heat resistant tape that the turbo guys use on their pipes.

Took it to the dealership for them to check it out and on my receipt it says "found NATS code. Cus does not have oem key. Rec new key and program" So pretty much the guy who was handling my car said the reason my car did that was because I don't have an OEM key (I have an aftermarket ilco key that seems to be working just fine) and the key didn't communicate with the BCM properly. The part I don't get is, if it didn't communicate with the BCM then why did they key let me start the car and every other time in the past 2 weeks I've owned the car.

Any help would be greatly appreciated.