U0073

[Sequential6.4L]

Having issues with my truck, no engine light just have a DTC U0073 which is something like communication bus A off.. ive also had other codes for loosing communication with power train control module. unless the dtc's are erased the truck wont turn over also whenever the engine is running the fan clutch is engaged and the fan runs non stop. Ive heard this can be caused by a bad dash daq or dash daq cable..ive tried the recommended method of removing the dash daq and cable but it has not fixed the problem, ive also tried changing tunes but that didnt correct the issue but it did seem to stop all the flashing lights and warnings on the dash the came along with this. any idea what the issue is fellas? and what it takes and costs to get it fixed? ive heard just a simple reflash from the dealer can fix it..should I remove my spartan TCM for this?

 

[Jeff@Spartan]

U0073 - Control Module Communication Bus A Off

Description: This DTC is set when the controller area network (CAN) between the powertrain control module (PCM) and data link connector (DLC) is open.

Possible Causes: • Communication error

Diagnostic Aids: Network DTC concerns occur during module-to-module communication. For additional description and operation of the vehicle communication network, refer to the Workshop Manual Section 418-00, Module Communications Network.

 

[TripleE44]

I get this same code every time I scan with my live wire. Just clear it and keep going.

 

[Sequential6.4L]

it instantly comes back up every time its erased in my truck.

 

[Scottbigred]

I'm having the same issue. It will happen, I'll clear the code and it'll happen right away again. Then it will be two three weeks before it comes back. Its annoying. I have seen quite a few people post about this but have never seen an answer as to what solves the problem.