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Caravaneer2
04-05-2015, 05:19 AM
My 06 Navion (3500 & 5 cylinder) has been having expensive trouble with sensors and now the ECU. Last Tday we were in the Mojave on an Interstate and I switched off the cruise control. Lost power immediately; even in neutral engine would not rev about about 800 rpm. Engine light came on. Then the power loss (limp home mode?) went from some of the time to all time so I had us towed to the Dodge dealer in Victorville. The single Sprinter tech there diagnosed failed MAF and APP sensors which cost about $1500 to replace.

This week and about 800 miles later ECU light again and same symptoms. We drove to Las Vegas this time (Henderson actually) to the Mercedes dealer. We got 98% of the way there with no symptoms, but the last mile or two were scary; loosing power in an intersection while your light turns red is not fun. This is a busy Sprinter shop which gave me some confidence; I gave them the Victorville work order hoping it would help spot any patterns. Next day they said the APP was shot. I said "again, after 800 miles? What is the underlying cause?" Blank looks all around. Engine light and LHM again even with the new APP in the time it took them to drive it from the back of the shop to the front and hand me the keys. Next day they decided it was the ECU which "probably" fried the MAF and APP sensors. They want $2000 to replace the ECU.

It helps to vent, but I actually have some questions: Has anyone had the ECU fail? Were the Victorville and Henderson shops inattentive (if not dumb) to not diagnose the ECU in the first place? Does anyone have a guess if the new ECU will solve this problem? Does anyone have any experience with Mercedes of Henderson or the Freightliner dealer in Las Vegas? I did price the ECU elsewhere and the price seems in line.

Words of wisdom will be appreciated as well as encouragement if possible.

Thanks.

obie
04-05-2015, 11:54 AM
I read here recently in another thread that someone had a bad ecu, can't recall exactly the thread, maybe a "no start" thread? It was not a first choice fix.

lindenengineering
04-05-2015, 02:58 PM
The PCM (ECU) is very sturdy.

Its a generic unit made by Bosch which is programmed for a very wide range of vehicles powered by Bosch equipment. For example a "visual" of a Landrover PCM is the same as the MB Sprinter PCM!

They are integrally protected so that voltage spikes and short downs on the whole don't kill vital components and generally speaking I would say from experience that here will always be a few that might fail but mostly the issues I see with sprinters a poor circuit communication and wiring harness issue.

As with most problems posted I see no or few precise fault codes to really give an indication of the problem area but I would be checking the system as a whole before changing out a PCM.
Dennis

MercedesGenIn
04-05-2015, 08:57 PM
Hi there,

Its worth checking the large rubber grommet that the ECU loom passes through from the engine bay, it is not uncommon for water to pass down the loom to the ECU connectors. Likewise hidden rust perforation/poor sealing of the windscreen to the body aperture is often the culprit for leaking 'water-in-the-works'.
All this is seen in older UK Sprinters, though yours is perhaps a later model and probably suffered way less from poorer weather.

Just a worth a mention.
All the best
Steve

smiller
04-05-2015, 09:54 PM
As the others have noted a failed ECU is way down on the list of likelihoods, much more likely something external. Any experienced diagnostician would know this and if your current shop's attitude towards why the sensors are failing is a shrug, and their only guess is 'it's probably the ECU' then I'd find another shop. Or at least ask them what happens if they replace the ECU and the problem is unaffected.

Caravaneer2
04-06-2015, 12:24 AM
Thanks for everyone's help. There is a post about acronyms too which I agree with. I used the acronyms not to be cool, but because I don't necessarily know what they mean! But here is a shot it:

ECU: engine control unit - aka main computer? But what is
PCM? I don't know.
MAF: I don't know.
APP: I thinks it's accelerator pedal position

A major complication for me is that I had to come home to Northern California for medical reasons but my Sprinter is in Las Vegas awaiting the ECU. The fact that it is not stocked is maybe a clue to the accuracy of their diagnosis. Does anyone have any experience with other Sprinter shops in or near Las Vegas?

I'm going to call Doktor A in the morning. Thanks again.

John

Aqua Puttana
04-06-2015, 01:06 AM
Thanks for everyone's help. There is a post about acronyms too which I agree with. I used the acronyms not to be cool, but because I don't necessarily know what they mean! But here is a shot it:

...

John
Got your back. Some info is here.

DRBIII, DAD and some other acronyms which may come up

http://sprinter-source.com/forum/showthread.php?p=250048#post250048

:cheers: vic

lindenengineering
04-06-2015, 02:06 AM
Thanks for everyone's help. There is a post about acronyms too which I agree with. I used the acronyms not to be cool, but because I don't necessarily know what they mean! But here is a shot it:

ECU: engine control unit - aka main computer? But what is
PCM? I don't know.
MAF: I don't know.
APP: I thinks it's accelerator pedal position

A major complication for me is that I had to come home to Northern California for medical reasons but my Sprinter is in Las Vegas awaiting the ECU. The fact that it is not stocked is maybe a clue to the accuracy of their diagnosis. Does anyone have any experience with other Sprinter shops in or near Las Vegas?

I'm going to call Doktor A in the morning. Thanks again.

John

John
ECU:- Electronic Control unit-- Engine Control unit.
They are generic terms for the units which control the engine. Since your engine "computer" talks to the transmission controller (TCM) to a certain extend we professionals tend to call it a PCM Power Train Control module.

MAF Mas Air Flow unit
Converts air going into the engine in Lbs or KGs into an electrical signal sometimes digital to let the PCM (computer) know how to set the fuel demand at any one time.

APP a term used to mention the Accelerator Pedal Position switch.
Being "drive by wire" the PCM needs to know what you are demanding of the engine by how much you are pushing down the pedal.
This is a linear rheostat and the ohmage output sent to the PCM knows what you are asking of it and sets the fueling map.

If I had the codes and the diagnostic evaluation from the two shops at hand I might be able to give you some alternative ideas of why the van is dead in the water.

In any case we have a "neutred" Sprinter T1N, PCM on hand for shop use to quickly rule out any internal control faults and we have on other cars had the PCM/BeCM & security modules reprogrammed to fit a ailing car should the need arise.
Its not a "black art" as many keep telling me be rest assured .
Like tuning 4 Stromberg or SU's on a V12 jag!
Or Del-Ortos on a Maserati.
Dennis
ps /BeCM: Body electrical Control Module

Tplumbn
04-07-2015, 03:18 PM
I have a 2006 3500 that appears to have a faulty ECM (ECU). I had previously posted a thread about it. My van is in a "Crank but will not start" condition. I sent the ECM out to SOS Diagnostics yesterday to either have it repaired or replaced with a "re-manufactured" unit. The dealerships cannot/will not install or sell anything but new parts so I am avoiding them as best I can in this situation.

I had left a message for Doktor A & he returned my call just as I was heading out the door to ship the unit off. He was also skeptical at first that the ECM was the cause. He said that he did not have the 2356-002 code that my Autel scanner was giving me listed in his notes, but had the 2356 code with a 008 sub-code. He told me that it appeared that I was on the right track after reviewing all of the codes that my scanner gave me. He gave Chad @ SOS his endorsement when I told him I was getting ready to ship it out to them.

I would have loved to have him look my van over, but he is about 300 miles from me and I am running out of time to get it working again and would have to get it shipped over to him and it is fully loaded with plumbing tools and stock. It would be a daunting task to unload it all and reload it afterwards. I will only resort to that if the van will not start after I get the ECM back.

I hope that you get your problem resolved soon.