Sprinter-Forum    
 

Go Back   Sprinter-Forum > T1N Sprinters > T1N Talk

T1N Talk General Discussions related to T1N Sprinters.


 
Thread Tools Display Modes
Old 01-10-2019, 10:40 PM   #1
quillaja
 
Join Date: Oct 2015
Location: Portland, OR (2004 2500 140WB)
Posts: 187
Thanks: 167
Thanked 86 Times in 57 Posts
Thumbs up Loss of Turbo/LHM solved!

Hi. I had previously posted (almost exactly 1 year ago) a desperate plea for help regarding a case of LHM / loss of turbo that was incredibly hard to diagnose. The thread relating to that can be found at https://sprinter-source.com/forum/sh...ad.php?t=62456

I'm happy to report that my issue is now resolved. TLDR: it was a bad ECU. I don't know exactly what aspect of the ECU was bad, but I highly suspect something like a cracked solder connection.

The longer story that comes after the thread above is that I continued to poke around and try stuff. When the LHM would occur, giving the ECU a sharp whack with my hand most often got it working again for a time.

I examined the various wiring in the driver foot well area, in particular the fat wiring harness leading into ECU C2 connector, for chafing or fraying. I also checked its branches out in the engine compartment. I couldn't see any thing that looked problematic.

I swapped in a new fuse box, thinking that perhaps some connection in there went bad, but that didn't help. I replaced the intake hoses (but not the intercooler) for good measure, although I didn't really suspect them. That didn't fix the problem...though I did have to cut out the old plastic coupler where the MAP and IAT sensors go because the bolts rusted into the brass inserts...fun.

I examined and cleaned a number of related ground points, but that didn't do the trick.

I retested all the wiring to the turbo actuator, GPM, and O2 sensor. All the wires seemed to have continuity, grounds went to ground, B+ lines had ~13v with the engine running, etc...

After that, there was nothing else I could test, so I finally called SOS Diagnostics and sent my ECU in for testing. I wrote a condensed description of the symptoms for them, which you can read here on google docs if you're so inclined.

About 1.5 weeks after dropping the ECU off, SOS called me, said they duplicated my symptoms in their bench tester and also in their sprinter, that they went ahead and copied my ECU programming to a working ECU, and the bill. I would have preferred if they had called be BEFORE going ahead with the new ECU, but I was going to get a replacement from them anyway... so whatever.

That was about a month ago, and I've been driving the van nearly every day since with no problems.

So I suppose the moral of the story is that if you have really hard to diagnose problems that seem electrical in nature, perhaps it could be the ECU if you've ruled out easier and cheaper things.
quillaja is offline   Reply With Quote
The Following 8 Users Say Thank You to quillaja For This Useful Post:
Aqua Puttana (08-16-2019), autostaretx (01-10-2019), billintomahawk (08-17-2019), GPLYNCHBURG (02-03-2019), Martin Duffy (02-08-2019), Midwestdrifter (01-11-2019), Mike DZ (01-10-2019), robphxaz (02-09-2019)
Old 02-08-2019, 08:51 PM   #2
Martin Duffy
 
Join Date: Jan 2010
Location: Australia
Posts: 134
Thanks: 9
Thanked 8 Times in 7 Posts
Default Re: Loss of Turbo/LHM solved!

Quote:
Originally Posted by quillaja View Post
Hi. I had previously posted (almost exactly 1 year ago) a desperate plea for help regarding a case of LHM / loss of turbo that was incredibly hard to diagnose. The thread relating to that can be found at https://sprinter-source.com/forum/sh...ad.php?t=62456

I'm happy to report that my issue is now resolved. TLDR: it was a bad ECU. I don't know exactly what aspect of the ECU was bad, but I highly suspect something like a cracked solder connection.

The longer story that comes after the thread above is that I continued to poke around and try stuff. When the LHM would occur, giving the ECU a sharp whack with my hand most often got it working again for a time.

I examined the various wiring in the driver foot well area, in particular the fat wiring harness leading into ECU C2 connector, for chafing or fraying. I also checked its branches out in the engine compartment. I couldn't see any thing that looked problematic.

I swapped in a new fuse box, thinking that perhaps some connection in there went bad, but that didn't help. I replaced the intake hoses (but not the intercooler) for good measure, although I didn't really suspect them. That didn't fix the problem...though I did have to cut out the old plastic coupler where the MAP and IAT sensors go because the bolts rusted into the brass inserts...fun.

I examined and cleaned a number of related ground points, but that didn't do the trick.

I retested all the wiring to the turbo actuator, GPM, and O2 sensor. All the wires seemed to have continuity, grounds went to ground, B+ lines had ~13v with the engine running, etc...

After that, there was nothing else I could test, so I finally called SOS Diagnostics and sent my ECU in for testing. I wrote a condensed description of the symptoms for them, which you can read here on google docs if you're so inclined.

About 1.5 weeks after dropping the ECU off, SOS called me, said they duplicated my symptoms in their bench tester and also in their sprinter, that they went ahead and copied my ECU programming to a working ECU, and the bill. I would have preferred if they had called be BEFORE going ahead with the new ECU, but I was going to get a replacement from them anyway... so whatever.

That was about a month ago, and I've been driving the van nearly every day since with no problems.

So I suppose the moral of the story is that if you have really hard to diagnose problems that seem electrical in nature, perhaps it could be the ECU if you've ruled out easier and cheaper things.

Fantastic result and well done for hanging in there. How much did it cost?
Martin Duffy is offline   Reply With Quote
Old 02-09-2019, 02:15 PM   #3
glasseye
 
glasseye's Avatar
 
Join Date: Sep 2007
Posts: 4,015
Thanks: 980
Thanked 1,870 Times in 1,010 Posts
Default Re: Loss of Turbo/LHM solved!

Thanks for the update. One more example of SOS Diagnostics saving our collective ass.
They solved an RKE problem in Frito that eluded three dealers and Doctor A.
__________________
"Frito" : the potato chip truck. 04 Hi-Roof 140 cargo.9800 miles by PO
150K miles in 10 summers. Fuel, filters, oil, tires, bulbs, batteries, front brakes, serp belt and tensioner, upper charge air hose, Cyl 3 failing GP.
Accompanied and assisted by "Cheeto", a 2019 Rad Powerbikes Rad City Stepthrough.

"Travels With Frito" Global travels by van, motorcycle and other www.petercmclennan.com

Absent this forum, I'd never have bought a Sprinter.
glasseye is offline   Reply With Quote
Old 08-16-2019, 02:54 PM   #4
quillaja
 
Join Date: Oct 2015
Location: Portland, OR (2004 2500 140WB)
Posts: 187
Thanks: 167
Thanked 86 Times in 57 Posts
Default Re: Loss of Turbo/LHM solved!

Quote:
Originally Posted by Martin Duffy View Post
Fantastic result and well done for hanging in there. How much did it cost?
I think it was about $700 total.
quillaja is offline   Reply With Quote
The Following 2 Users Say Thank You to quillaja For This Useful Post:
Aqua Puttana (08-16-2019), billintomahawk (08-17-2019)

Tags
boost, limp home mode, module, turbo

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump



All times are GMT. The time now is 02:53 AM.


Powered by vBulletin® Version 3.8.9
Copyright ©2000 - 2020, vBulletin Solutions, Inc.