2500 Sprinter glow plug CEL issues

foodstampman

New member
We bought our 2006 Sprinter brand new as a Pleasure-Way Motorhome in 2006. It is a 2500, OM 647, T1N, NAG1, 158", high roof, with 16" rims. We now have almost 155,000 miles on it. About 15,000 miles ago the transmission had to be rebuilt by a local transmission shop. Under the right conditions, shortly thereafter, we got a CEL. My little scan gauge code, when looked up, pointed to glow plug 3. After a month or so, when we got the CEL light, we got a second code: now it was glow plugs 3 and 4. When the 3rd code appeared, naturally, it pointed to the glow plug control module. Since I was driving in warm weather, we were told by out local mechanic that it was not a serious trouble, and ignore it.
This spring, after a year of occasional CEL lights, we took it to Freightliner/Sprinter for service, as starting was getting harder when cold. We carefully explained that the CEL light comes on only under these certain conditions: When it is 60-65 degrees or colder, we start the RV, move it 20 to 40 feet out of the enclosure to load it, but shut off the engine while loading. It never warms up. Upon restarting, we get the CEL within seconds of starting it. These are the conditions that always bring in the CEL. Three codes: always the same now. Glow plugs 3 & 4 and the glow plug control module. If started, but not shut off until the engine warms up, there is no CEL upon restarting.
My local Freightliner/Sprinter dealer service handles many Sprinters, as well as selling them. They have a wonderful policy that if they do not fix it right the first time, bring it back and they will work on it again, no charge. My RV has been in and out of Sprinter service for 7 months now, and the condition has never been resolved. After discussing it with both the mechanic who worked on my RV, as well as his boss, more than once, they are at an impasse. No solution.
Done so far, in a nutshell: Glow plugs were changed, then rotated. Codes for GP 3 & 4 did not move when GP 1 & 5 were rotated into 3 & 4. Wires and wire connectors were checked, substituted, as well as the control module. I do not know which new style control module I bought, but it did not change one thing !! Next, I bought the new engine computer module for over four figures, but nothing changed. I am awaiting a refund on thet part, as my ols one was put back in, and nothing changed. Same 3 codes, when restarted after shutting off cold.
The next thing the the Benz support team suggested was the wiring harness from under the dash, thru the firewall, to the engine, as the old wiring harness was rubbing on the large battery that was under the hood. The tech did a beautiful job replacing that wiring harness, making sure the new one did not rub the battery any more. We were certain THIS would finally solve the CEL issue. NOT !!
Now Freightliner is saying that short of changing the chassis harness, there is nothing left to do. Also, they do not change the chassis harness, as it would mean cutting the vehicle apart in places, and it is not worth it to do. I got the impression they only tried that as a last resort for a vehicle that is under warranty . . . something my 12 year old RV is not.
The glow plug control module is not my original now, but my engine computer module is back to the original. The glow plugs have all been swapped all over, but only 3 & 4 ever throw codes. It makes no difference on the GP's if they are steel or ceramic, or where they are in the engine, if that makes any difference. Same codes: GP 3 & 4. NO OTHERS, ever.
It is not like they had the RV in and out quickly, as in Sept and Oct, it lived there while they tried everything they could think of. When started cold, run briefly, shut off cold, and restarted, it gives the 3 CEL codes. Restarting could be within minutes, or even the next day, as long as it is 60-65 degrees outside. When 75 degrees and above in the summer, you can not bring in the CEL regardless of what you try. Under all circumstances, we ALWAYS wait for the glow plug indicator-light on the dash to go out before we ever try to start it, and always have.
Freightliner has done what they say they can do. Does anyone out there have any suggestions ?? I have read a number of GP issues on the forum, but I have never seen this issue, So, what now, because Freightliner has given up on my Sprinter now ?? They say that it seems not to be a "real" problem, and I should go on ignoring it by clearing the CEL alarms, but watch that it is always the same 3 known codes I retire and clear. Of course, if other codes come in, I'll have them checked out immediately.
Thank you for any help.
 
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