No Bus issues will start and run

[Mdob2000xj]

Hey All, I’ve read quite a bit on these forums but never posted. I’m looking for help as I’m lost on this No Bus issue. It all started when I was doing my heater core. I took the dash out completely, unhooked all the wires and removed it from the vehicle. After I finished the job I put it all back, and had 0 no bus related issues. When I charged the AC system, I realized I had a blend door stuck open. I pulled the dash again, this time without disconnecting wires or removing it from the vehicle. I was able to fix the blend door and put the dash back.

When I reinstalled the dash and cranked it up I had the dreadful no bus code. My symptoms included erratic gauges, door locks operating overhead lights, rear wiper always on, rear defrost light always illuminated. Also CEL is on as well as the airbag light.

I’ve driven it a few days with this issue and the symptoms have slightly altered. I’ve noticed my horn doesn’t work, except when I hit the lock button and it goes off! The passenger door actuator will sporadically go off and hold, even started smoking while I was troubleshooting.

One thing I noticed that seemed strange, the wire that runs to the ignition switch felt hot, specifically on the section where it has a metal cylindrical piece.

In my attempts to fix this, I’ve removed the instrument cluster and cleaned the connections and reinstalled. Looked for broken/pinched wires. Removed, cleaned, and added dielectric grease to engine bay grounds. I also checked the module located under the glove box which was tightly secured.

I’m at a complete loss and don’t know where to go from here, especially with smoking components. Any advice would be greatly appreciated!

 

[Mdob2000xj]

Not located under glove box, under center console***

 

[Tim_MN]

..... symptoms included erratic gauges, door locks operating overhead lights, rear wiper always on, rear defrost light always illuminated. Also CEL is on as well as the airbag light.

The symptoms suggest a short circuit to ground, or to another wire in the wire harness.

Wire harness failures at the drivers door and the tailgate are common. Often the wires in or near the rubber boot/hinges will break, or the wire insulation simply fails and falls off.

I would begin by disconnecting the drivers door and tailgate wire harnesses from the body harness. I might even unplug the front passenger door. Visually inspect the wires and test wire continuity. If the symptoms persist, unplug the horn relay.


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[Mdob2000xj]

Thank you I will look into this as soon as I get a chance and report back what I find.

 

[Mdob2000xj]

If anyone is looking for the solution, I just fixed mine today and here’s what I did. I tried it all, cleaned instrument cluster, cleaned grounds G108, G107, G106, G100, G101, G102, bought a junkyard instrument cluster, pulled dash and cleaned all connections and checked for continuity and bent pins. None of these did anything.

Here’s what did it for me. When I pulled the dash and put it back, the two bolts that secure the dash on the bottoms corners (with a C bracket and a bolt), I didn’t tighten them back down all the way. I assumed the 5 bolts across the windshield would’ve given continuity from dash grounds (g108, g107) to negative terminal but apparently not. Those two bolts on the bottom seem to be the only path for the current to flow, so tightening them down all the way fixed all my problems.

Such a simple fix after days on end of troubleshooting. So word to the wise, if you pull your dash, tighten those bolts all the way!