Random fault in wiring harness
 

Hi. I have a 2008 wrangler and the other day I got a p1221 code for the throttle body not opening. The jeep was driving fine till all of the sudden it was spuddering and bucking. I had it towed home and I traced a break in the wire to the big disconnect plug on the firewall. After opening I tested continuity on both sides and it was good. So I closed it back up and started the jeep. It now runs perfect again.

My question is, what would cause something that supposedly hasn’t been touched in 14 years to become disconnected? Is this common, should I open and reset all the other connections too? There were no signs of corrosion but should I spray with contact cleaner? Would it be wise to lube all the waterproof seals with dielectric grease? Just don’t want it to happen on another system as it is our daily.

Also, last week, we did have a short in the ignition coil that was grounding cylinder 3 via the pcm. Could that have contributed? I haven’t checked the pin out of that connection to see if they are close and might have arced.

Maybe the connector was never "locked" in place since new. Given the Jeep is 14 years old it wouldn't hurt to unplug major connectors and lightly lube with proper electric grease but be warned that old connectors can break due to heat cycles etc. It might be best just to ensure all connectors on the ECU etc are just tight "locked" into position.