2018 FCC Warning

[Maxisp1000]

I have a 2018 Pace Arrow diesel pusher. ISB 6.7. It has less than 30,000 miles.
The engine flashed a STOP ENGINE light in the mountains. I called Cummins and it threw code VGT Failure SPN 102 FMI 1 OC 1.
It was towed to nearest Freightliner (FL) dealer and they said that code Cummins 4729 requires a new wastegate and turbo. One year out of warranty.

Being stuck hundreds of miles from home I authorized repair for just under $12,000.00. After a week, we payed the bill, picked up the RV from the dealer to go home and it failed again in the next mountains with the same code, less than 100 miles away. Luckily I have a friend who is a FL master mechanic. He said as long as we have good oil and coolant we can get it home. I restarted engine briefly 3 times for 60 seconds and the red light went off, leaving the amber notification engine light on. I nursed it home for 2 days on the shoulders and road at 55 mph.


I took it to my local dealer and they found FL PN 01-33449-000 (mfg date 7-2017) to have a crack on the inside radius and at a hose fitting. That part is $41 and 2 hours shop labor. They said this was an old failure by the wear on the part.

This is the rubber fitting from the turbo to the air compressor. The first shop charged me extra to lift the bed for access. This part is literally inches from that opening.

This hose is not covered under the Cummins procedure for this failure code as it is a FL part. FL does not have a procedure to follow either. The coach has been 100% FL dealer maintained at all service intervals. Several FL dealers missed it for years, it's not on the recommended service checks.

This is a gap that relies on the skill of the worker to find and fix.


Are there any safety bulletins out there for this? If the compressor fails and you lose brakes and air bags is unthinkable.
Are your mechanics checking this low quality rubber hose from CHINA during maintenance?
Where does it say anywhere in the FL documents to check this unit.
AND
Have your FLCC unit checked for this as soon as possible.

[d23haynes57]

For the cost of that repair, I would have turned back. Besides the fault code what other condition indicated turbo and wastegate replacement? These are mechanical parts that can be inspected once they are out.

[J_C]

4729 is for low intake manifold pressure. That hose you are referring to is the intake hose for fresh air into the air compressor. It is under boost pressure when the engine is running since it is hooked up to the charge air cooler.

This is a very very common failure on the RV chassis’. The p clips that hold the hard steel pipe break cause fatigue on the hose. I have found this every time the hose has failed. Mechanics look over this hose during the inspection because of inexperience. One of the steps in troubleshooting states to inspect for air intake or boost leaks which the first shop missed. If the hose was replaced, the p clips should have replaced as well since they are most likely broken.

Im sorry to say this but the first shop didn’t diagnose this correctly. It could have been a turbo but this is probably the least likely part it could have been.

[Maxisp1000]

@ J_C Thank you for the message. I agree.


I have the troubleshooting tree and I can find no mention of inspections for this hose during troubleshooting.


Is there a publication number?
Also,


If this is a common issue, as my sources says, then where are the FL instructions to check of this part during routine maintenance?

[J_C]

Cummins troubleshooting tree states to inspect for air intake leaks. It does not specifically mention this hose. Section 13-01 of the RV chassis Maintenance Manual thru FCCC states to inspect this hose at regular intervals. Most mechanics are not looking at this hose. The issue would first appear with those p clips broke. If they were broke, I would inspect the hose. It’s kind of why I said inexperienced mechanics were the issue. They probably didn’t know this hose is under boost pressure. There is no bulletin from Cummins or FCCC about this issue. I’ve replaced the hose and p clips every time I found them broken.

[vettenuts]

Is this specific to the ISB, or will the ISL have a similar issue?

[Maxisp1000]

If anyone wants to know if this part or a similar part is in the engine, contact DTNA Support online and start a thread there. I got a drawing to see where it is.

[Pol6]

Just as detailed by Maxisp1000, got the same ‘trouble lights’ on my display while driving threu mountains in Mexico between Mazatlan and Durango. Not a good place to be in trouble of any sort.
I was lucky enough to find a place to pull of the road and try to resolve the problem. I check all fluids and temps and all were ok, tried the reset with battery disconnect. Still had the red and amber engine warning lights. Decided that I had not much to loose so carried on and made it to Durango with now only the amber check engine.
Found this post and started to ‘dig’ in the engine bay to finally find a cracked rubber elbow just as described by Maxisp1000. Fortunately there is a freightliner dealer in Durango and they found me something that could be used. I installed it and ‘voilà’ the engine is running normally. Actually it seems to be running better than during the last months.
This forum is of great help, thanks to all !

[Maxisp1000]

I am so I glad I was able to help someone.


This is a serious issue and is a gap in Freightliner and Cummins procedures.