2006 silverado limp mode with HID's

**spencer** · 04-03-2009, 12:52 AM

I've got an issue with my bosses truck. It is a 2006 silverado with a 5.3 "B" motor. It goes into limp mode at first start up. It has all the stock headlights replaced with HID's. The low beams and fog lights both are hooked up to a relay kit. If you turn the headlights on and off you can get the truck to go back into limp mode after clearing the codes. The PCM is under the hood and pretty close to where the ballasts are mounted. I was wondering if anybody has encountered this, and how to isolate the ballasts. My theory is that their is some sort of radio interference from the ballasts. i get a passel of codes when it is in limp mode, all related to the app or throttle body. i've replaced the throttle body twice, reprogrammed the pcm and checked all of the wiring. The only additional info I have is that I could not program the PCM in the vehicle, I had to do it in another vehicle. Im looking for a way to isolate the ballasts because im pretty sure he doesnt want to pull them out. thanks
spencer

**bry2500** · 04-03-2009, 03:33 AM

Sounds like a wiring messup. It will be a pain but to get it done right you may have to pull em out and start from scratch on the install. Even go back to stock headlights and see if the problem goes away. if it doesn't them I would say it's a new PCM for the truck. hope it all works out.

Welcome to the site!!!!!!

**Z71_guy** · 04-03-2009, 09:13 AM

welcome to the site

**Jimmiee** · 04-03-2009, 11:20 AM

Please post the codes. The actual code(s) tell you exactly where to start your diagnosis. Also exactly when does the code set?

**dwill3015** · 04-03-2009, 09:50 PM

Welcome to the site and as Jim mentioned, post those codes!

**bob13** · 04-04-2009, 12:52 AM

Welcome, the frequency idea does not sound right, post the codes and I am sure the guys on this site can help you!

**spencer** · 04-04-2009, 02:27 AM

Originally Posted by bry2500

Sounds like a wiring messup. It will be a pain but to get it done right you may have to pull em out and start from scratch on the install. Even go back to stock headlights and see if the problem goes away. if it doesn't them I would say it's a new PCM for the truck. hope it all works out.

Welcome to the site!!!!!!

They are plug and play, even with the relay kit, there really is no way to mess up the wiring. i read somewhere else last night that a bad ballast can cause it, so i swapped out the ballasts for some spare ones we had laying around. i couldnt get it to duplicate after that. as for as when it happens, it used to happen going down the highway, but now it only does it at startup.