Howdy. At 94K miles my '14 GLK250 check engine light came on for the first time. Went to my local garage (not a dealer) and he read it as a malfunction of the DEF heater unit. Obviously in South Carolina we don't need a DEF heater (it is programmed to come on only in extremely cold temps), but the shop could not clear the check engine warning. Note: got the check engine light but NOT the "ten starts remaining"

Dealer wants $1700 for a replacement; my shop will do it for $1430 all in. But my shop alerted me that the current diesel recall may well cover this repair. I checked with the dealer, who told me that in about a month they would get clarification on this but they were optimistic. Both the dealer and the shop advised me to continue driving the car -- the only downside is that I won't notice if any engine fault triggers the check engine light. This is the first time it's ever been lit, by the way.

So obviously I'm going to drive it for a month with the check engine light on. And I guess now I'll get the recall done (it pays out a hefty sum to us original owners, as y'all likely know), even though I have been having major qualms about future performance and fuel consumption after the recall is done.

My question is whether others have had this DEF heat assembly issue? If so, what have you done? Thanks.

 

Did you top DEF tank?
There is not really a recall. In USA we do have MB settlement and you should get a letter about it.
The job scope is outlined here https://www.epa.gov/enforcement/daim...vil-settlement
Doesn't look like your DEF tank will get replaced with it, however the extended warranty might cover it in the future.
It is pretty tricky legal situation and we will see how dealers will play it.
But if your heater can be replaced as single unit, it should not be that expensive?
BTW we just hit 90's F in Las Vegas and we did 1st pool splash of the season, so assuming weather pattern is similar in your location, you will not need DEF heater for several months to come.

 

In my experience with the same vehicle and year, the check engine light comes on and then many mile later the countdown starts. I pulled the tank myself and replaced it with a Xemodex unit for $550. It took several hours, which I spaced over a few days. It is not that difficult with the vehicle on Jack stands and the DEF tank emptied. There are Youtube videos and the Xemodex unit comes with good instructions. You don't need the functionality of the heater where you live, but you need the system to see it is functioning. The heater is not a listed part under the emissions campaign. The dealer's proposed fix prior to the campaign was to replace the entire tank system as one unit for an estimated $3,000 - $4,000. They didn't like the idea of doing all the labor to replace the heater when later the temp sensor or level sensor could fail. The Xemodex unit replaces the heater, level sensor, and temp sensor with more robust components than the low quality Bosch components that are a weak point in the system.

 

I appreciate your message.

I just checked with the service manager at Carlton Mercedes in Greenville. He assured me that the GLK will NOT go into limp mode, and will NOT ever give me the "10 remaining starts" message, for this particular error message, unless temps descend into what would be ice age conditions for South Carolina (lower than -20 degrees F). I am nonetheless going to schedule the recall right away, as the recall is the only way to get the extended warranty which covers the DEF heater assembly.

We love our GLK, and I'm worried that the recall will greatly deteriorate its ride and consumption characteristics. What do y'all think?

 

So far all reviews of modifications are positive. I drove my Sprinter with OM651 engine for 40 years and did not notice any difference in performance.
Other members report increased mpg, but with low miles driven there is no firm conclusion.

 

That's what I was also told by the dealer. "Just drive it that way until the campaign is approved or pay us to fix it and try to get reimbursed later." "We don't know what will be covered yet." So, I did. It started blowing white noxious smoke. I could not drive it with that toxic white cloud, so I brought it in to see what could be done. The dosing valve was replaced. Still blew white smoke. I called in to let them know it wasn't fixed. Same reply, pay to have all the sensors replaced and the entire DEF tank system at my cost or wait until the campaign was approved. I drove it rarely and then the countdown started. My analysis is that the initial fault in the system triggered some ECU or HCU algorithm calling for more DEF which fouled all of the sensors.. A cascade of codes followed involving the dosing valve, NOX sensors and PM sensor. With all that, the countdown started and it went into long storage. Still not home.

 

My letters have a list of over 20 parts that are covered by extended warranty, but also a note "any component which can reasonably be impacted by effects of the emissions modification".
Sure sounds like can of worm to open.
My Bluetecs all have high mileage, so I take the extended warranty now.
Beside the settlement says about covering 85% of affected fleet, what I think might give MBUSA rights to refuse the job on late owners.
Again, my interpretation and sure heck of the settlement to interpret.

 

Two weeks before I was scheduled to get the settlement refresh done at the dealer's (Carlton Motorcars in Greenville, SC), my GLK started emitting an awful ammonia smell with white smoke coming from the tailpipes. So I headed to the dealer without an appointment. On my way there, the AdBlue low warning message displayed on my screen (this in addition to the CEL for the DEF heater discussed earlier). I left the GLK at the dealer for the settlement refresh and (I hope) for extended warranty replacement of the DEF heater unit once the settlement work is done. Today's the 4th day since I dropped off the car. No loaner (they would have given me the loaner for the settlement work had I waited until my appointment date, but I couldn't go two weeks with that awful smell and smoke.).

 

Very good news. The campaign fix has been performed. The CEL for the DEF heater was deemed related as per the settlement, and was fixed free of charge. All fluids replenished, and the car was even hand washed. No dispute or difficulty with the dealer at all. On the drive home I sensed no loss of power, and the MPG was 33.3, which is what it usually is for the 40 mile mix of highway and town driving. So, count me satisfied. Now I'm going to fill out the paperwork to get my settlement payment.

 

Good to hear they applied the warranty to condition before AEM.
I did wonder how dealers will play that. In my case they wanted to charge me for new DPF, who had leak, when DPF is part of new warranty, so it is individual decision.

 

Can you reference what part was replaced to rectify the issue with the Adblue heater? They don't specifically list the heater as one of the parts covered under the extended warranty but If i'm not mistaken that's because it's part of a larger component that IS covered. I ask only because my dealership is giving me such a hard time with replacing these parts despite having an effected vehicle with a CEL for P203D "reductant level circuit high"

 

Sure. The CEL was fir "REDUCTION AGENT (ADBLUE) - HEATER ASSEMBLY - DEFECT. The OE is A2044710575, part alone is $1490 at dealer's. On my invoice they indicate having replaced it because the check engine light was on "due to campaign concerns."

The other parts replaced or remanufactured were:

• 204490040085 TS diesel partic.
• 204490050085 TS oxidation cat.
• 204490010080 exhaust gas line
• 204905460585 tx nox sensor
• 0005849613 information label affixed
• 007604018109 screw plug
• 0219976245 profile sealing ring
• 0005454039 plug housing

They noted the following: "Pressure differential sensor pipe fitting at rear of DOC unit pulled threads off of old DOC connection. Was able to save sensors fitting by cleaning threads out of fitting.

 

Thanks, I would think it would be the same considering we have the exact same year/model/issue but it seems like they are ll over the place with these repairs depending on which dealership it's brought to.

 

Well, I wish there were no more to say after the diesel emissions campaign was performed, and my DEF-related check engine light cleared, at no expense to me. But there is MUCH more to say.

Recall: Carlton Motorcars (Greenville, SC) performed the campaign and cleared the DEF engine heater assembly warning light, replacing multiple parts to do so, allegedly.

Then I undertook at 600 mile trip to DC (to see grandkids). 100 miles into the trip the check engine light lit up again (but there was no verbal "check DEF" warning unlike earlier). I drove to DC and contacted the nearest dealer (Euromotorcars in Bethesda, Maryland -- coincidentally the shop where I had purchased the GLK before our retirement/move to SC). They performed a diagnostic test (which they said would have cost me $169.95 were it not campaign related) and they did a "multipoint check" at no charge. They found a "historic" code for the same DEF heater assembly. They cleared the code and told me I was good to go, the GLK checked out perfectly after a test drive and it was only an "electronic glitch."

Two days later I drove back to SC. 15 miles into the trip, the check engine light lit up again. It stayed lit for the whole trip home. I phoned Carlton en route and they told me to drive home but to stop and have the car towed if the CEL started flashing or if I got any verbal warning. It didn't and I didn't. Carlton made an appointment for me for JUNE 7 (!!!), the earliest possible date for a non-emergency.

That was yesterday. Today, 3 miles into a 50 mile trip my car started spewing huge totally white billowing clouds of what looked and smelled like ammonia (i.e., DEF) whenever i touched the accelerator. Rushed back home, missed my appt., phoned Carlton, and three hours later a tow truck arrived to take the GLK to the dealer, at the dealer's expense. (I wasn't driving it when cumulus clouds issued forth behind the vehicle) They say they may need it "three or four days", they said.

Good news is it didn't happen on my 1200 mile trip to DC. Bad news is the campaign does not appear to have left my GLK in the tip-top shape the Bethesda folks diagnosed.

A "discussion" about whether I get a loaner will soon ensue.

My GLK (95K miles) was trouble free, totally trouble free, until the CEL light came on one week before the service campaign was performed. Now I don't know what to think.

 

When $169 for car scanning is total BS, I think you should buy a scanner.
Not only ScanGauge for diesel monitoring is highly advised, but you can buy Autel dongle for $49 and know exactly what is happening with your drive a moment after CEL illuminates.
IMHO there are no bad MB vehicles, but there is lot of bad MB mechanics.

 

Update as of May 12. My GLK is still at the dealership, and has been there for 1 week now. They say it continues to spew out DEF fluid liberally. They have created a case with MBUSA, and are trying fixes suggested by the head office. I have a loaner car (a Ford Fusion....).

Wondering if my GLK is the only casualty of the "campaign" to reprogram the diesel emissions?

 

DEF heater failure seems to be pretty common on Sprinters, but they have different technology.
The reservoir is in 5 gallon size, what last 5-7,000 miles and it is not serviceable unit.]
Means any heater or other part failure require whole reservoir replacement with ca $3k part cost. Forum wisdom says that if you keep DEF low in cold climate, the heater will not get enough cooling and it will burn itself.
One of the Sprinter owners just reported that his dealer covers the heater under extended warranty, even it is not listed on it officially. I can only wonder if MB USA will make it official with additional note.
The whole extended warranty will be very interested to watch IMHO.
Let's give it some time and see owners coming with 300,000 miles vehicles and needing valves replacement.

 

Update as of May 18. In the shop now for 13 days, still no news. I will try to contactd MBUSA if I get no news by Friday.

 

I just read on Sprinter forum that with AEM lot of Sprinters reported high DEF heaters failures and MB USA run out of stock for those parts.
There are not too many GLK bluetecs in America, but sounds like their parts might have the same problem.
Good luck with the repair.

 

After almostt 3 weeks, Carlton phoned to say the GLK was ready. Thjey had removed and reinstalled a tempereature sensor with integrated heating element, and replaced the Adblue metering valve. They also took it on a 60 mile test drive and the check engine light never came on.

They told me it was ready and to come pick it up. When I did, the windshield was cracked from bottom to top. [It was perfect when I dropped it off three weeks ago.] Carlton refuses responsibility. I have had to make an insurance claim. Windshield will be replaced Thursday.

 

What was their excuse for crack windshield?
Shops have insurance for such things, so not like they would have to cover the expense.
I would make official report to MB USA about it.

 

The service manager said I cannot prove that the crack wasn’t started when I dropped it off. I told him I dropped it off three weeks ago, that we did a walk around, and that nobody saw anything. He responded that there still might have been a tiny tiny crack and that I cannot prove the contrary. I have since spoken to MB USA and the rep was very surprised. But he has not gotten back to me.