Check engine light - No exhaust brake

[Clayduster71]

On our 5400 mile trip on my Seneca 39FS I had a issue I wanted to post it in here just in case anyone else has this in the future.

On July 4th while traveling east bound on I-90 heading from Mt. Rushmore, I had a check engine light that started randomly turning on for a few minutes then off. I immediately stopped and check all the fluids and did a good look over of the engine. I could find no issues.

On M2 freightliners, you can access the active engine fault codes thrown by holding the odometer reset button at start up. The code showing was a 641 with a Fail 7. Googling that code a forum said it was a turbo actuator fault. This made no sense since everything was working fine. We continued on our 1100 miles back to TN.

In Waterloo Iowa, I had the crap scared out of me. While traveling 70mph on the 4 lane, the exhaust brake engaged by itself while I was accelerating. The switch for the exhaust brake was not even on! At first I did not realize what was happening. It scared me so that I started looking for a mechanic to check things out. Since it was July 4th, I could get no help. We shut down for the night at the Flying J truck-stop there conveniently located beside the Freightliner dealer. But, this was Saturday July 4th and they would not look at it until Monday morning.

That night I read any and everything I could about what could have caused what was happening. The consensus online was the VGT actuator was faulty. These Cummins engines have a Variable Geometry Turbo (VGT). The turbo has a actuator on the side that drives a geared lever. The lever varies the internal workings of the turbo so you get immediate boost with no spool-up and also a very efficient exhaust brake.

The next morning, we got under way again since there was no way to get the RV worked on and it was operating properly other than the check engine light and the occasional exhaust brake coming on for half a second. I drove the 1000 miles home that Sunday.

That Monday, I took the Seneca to MHC Kenworth in Kingsport TN to see if they could figure out what was wrong. They called me in a few days and told me I needed to buy a Turbo and Actuator. It was going to cost $6500 to do it. I quickly asked the lady who called me what I owed them because I was coming to get it. A quick search online showed the best price on a full rebuild Turbo and Actuator was $2200. There was NO WAY I was going to pay $6500.

When I got the Seneca home, I took off the air filter canister beside the turbo. I carefully checked all the wiring from the ECM to the turbo. There were no frayed wires. I then pulled the Turbo actuator. To do this, you need to drop 5 gallons of anti-freeze out of the radiator because the actuator has it running thru to cool it off. Taking 5 gallons out drops the level below the actuator.

When the actuator came off, everything looked brand new. There were no obvious signs the actuator was bad (but its impossible to know). The turbo was definitely not bad. The VGT armed moved back and forth freely and had a very obvious "click" on both stops. This turbo was in very good shape.

A rebuild actuator ranged in price from 800 to 1200 online. I found a place in Illinois that would rebuild it with original components for $400. The name of the place is AVI Electronics. https://avielcorp.com/ I sent the actuator to them.

One of the hang-ups that keeps a typical "Shade Tree Mechanic" from installing a turbo actuator is the need for the new actuator to be calibrated prior to re-instillation. This is done at the truck repair shop usually by a cummins laptop program called "Insite". IF YOU REMOVE THE ACTUATOR, IT MUST BE RECALIBRATED. To get around this, AVI rents a very simple calibration tool for $80 they can send you with your rebuilt actuator. I opted for this option.

Friday I received the rebuilt actuator and calibration tool. 30 minutes later I was test driving the Seneca. Problem solved for under $600.

[SloPoke]

Great write up! How many miles are on our Seneca?

[DrSmart]

Yes, very good write up. We went through this last year with our 2014 Ram 3500. Also did a lot of reading on line. Opinions were mixed as to whether it was the turbo or the actuator. The dealership service manager communicated with Chrysler engineering and was told it definitely was not the turbo. They replaced the actuator and we've been good for several months.

[Clayduster71]

72,000 miles

[Murff]

So, does this mean Freightliner had no idea what was wrong and were trying to scr....

...take advantage of the situation?

Murff

[phuggit]

Thanks for taking the time to write up your fix. Much appreciated.

[Clayduster71]

When you mention the word "RV" at the Freightliner dealership, your per hour charge goes up 50%. They wanted $195 an hour there and were backed up for a week. They flat out told me they did not like working on RV's and to take it somewhere else. So much for buying their "brand", eh?

I took it to MHC Kenworth who is one of the largest dealers in the nation. They told me what the computer told them to do. $6500 would have fixed the problem for sure and most would have paid it. I just had a hard time believing a vehicle with 70k miles needed a new turbo and it didn't.

[Robbbyr]

Originally Posted by Clayduster71

When you mention the word "RV" at the Freightliner dealership, your per hour charge goes up 50%. They wanted $195 an hour there and were backed up for a week. They flat out told me they did not like working on RV's and to take it somewhere else. So much for buying their "brand", eh?

A number of us have experienced that answer when calling a Freightliner dealership and mentioning we need RV service. But many of us have found that when we further explain it is a M2 chassis (and possibly newer S2RV units) the tone immediately changes and they ask "can you drop it off tomorrow?". And the labor rate for the M2 is less than they charge for the diesel pushers.

My local Freightliner dealership has only 2 bays for pushers, the M2 goes right next to the semi tractors and delivery trucks in their other 20 bays!

[SloPoke]

Originally Posted by Robbbyr

A number of us have experienced that answer when calling a Freightliner dealership and mentioning we need RV service. But many of us have found that when we further explain it is a M2 chassis (and possibly newer S2RV units) the tone immediately changes and they ask "can you drop it off tomorrow?". And the labor rate for the M2 is less than they charge for the diesel pushers.

My local Freightliner dealership has only 2 bays for pushers, the M2 goes right next to the semi tractors and delivery trucks in their other 20 bays!

Same in Salt Lake City... Our Dealership just became a Penske owned dealership, but they always need to be reminded that it is on the M2 or S2RV chassis. Granted, they see very few Seneca's (in comparison to the DPushers) and they are pretty much trained to make sure they quote the "rear engine" rate to anyone who mutters the word 'motorhome'.

Be sure to make sure the person you are talking to knows you are on the M2/S2RV chassis or you will be pushed into the long line of DP's that the entire staff does not want to work on.

Every time I encounter a new service writer, I ask them to come out and get the mileage themselves.. Once they see the Seneca - they say Oh - I have this ticket written up wrong. (normally they are used to the driver having all the details they need when they check in at the service desk) You have to get them out to see your Seneca.