is it the check engine light that comes on? I have what sounds like the same issue. my check engine light has come on now 5 times, and they have replaced everything they can. They are now saying it’s the same issue as experienced with the GLE for which there is no software fix and that I should just drive the car with the light on until the software fix is available. Oh and apparently I now need new tires urgently despite the car having less than 20k miles.
GLC 350e cooling system issues
We purchased a new GLC350e last summer and have had chronic cooling issues ever since. Wondering if anyone else has seen similar problems.
When running on the battery we often get a cooling system fault light on the dash display. We’ve had the car in for service 7(!) times now and they’ve not been able to identify the source of the problem, much less repair it. I don’t see references to this sort of issue on this forum, so perhaps not a common occurrence?
Anyone heard of this sort of problem before?
So far the dealer has replaced one of the motor/pump assemblies, a temperature sensor, the controller for the coolant at the battery, the engine wiring harness, upgraded the software for the engine computer, and repaired a connection on the wiring harness. The problem is still there.
As much as the wife loves the car, we’re at the point of turning it back in as a lemon. If the dealer, the corporate office, and the factory all working together can’t properly diagnose and repair a problem than I don’t want to be on the hook for figuring out what it is when the warranty runs out.
When running on the battery we often get a cooling system fault light on the dash display. We’ve had the car in for service 7(!) times now and they’ve not been able to identify the source of the problem, much less repair it. I don’t see references to this sort of issue on this forum, so perhaps not a common occurrence?
Anyone heard of this sort of problem before?
So far the dealer has replaced one of the motor/pump assemblies, a temperature sensor, the controller for the coolant at the battery, the engine wiring harness, upgraded the software for the engine computer, and repaired a connection on the wiring harness. The problem is still there.
As much as the wife loves the car, we’re at the point of turning it back in as a lemon. If the dealer, the corporate office, and the factory all working together can’t properly diagnose and repair a problem than I don’t want to be on the hook for figuring out what it is when the warranty runs out.
1 - 13 of 13 Posts
Not a check engine light but a coolant symbol.
![3509]()
One of the attempted repairs was a software update which didn’t resolve the problem.
We’re turning the car in as a lemon. It’s a great driving car but I don’t want to be stuck with this when the warranty expires, especially if it’s so difficult to identify the root cause of the problem.
One of the attempted repairs was a software update which didn’t resolve the problem.
We’re turning the car in as a lemon. It’s a great driving car but I don’t want to be stuck with this when the warranty expires, especially if it’s so difficult to identify the root cause of the problem.
They say mine is a coolant/temp regulator issue too, but it’s the check engine light that keeps coming on. when you say you are turning it in as a lemon, what does that mean? Did you hire a lawyer or are working with the dealer? Thanks so much!
In the state of Washington, where I live (and in most others, I believe) there are laws regarding the reliability of new vehicles. Generally speaking, they can’t have numerous unresolved defects or spend an inordinate amount of time being repaired in the first few years of ownership. If either of these is the case the manufacturer can be made to replace the vehicle in kind or buy it back. The program in Washington is administered by the state attorney general’s office.when you say you are turning it in as a lemon, what does that mean? Did you hire a lawyer or are working with the dealer? Thanks so much!
When we made the decision to exercise our rights under the state lemon law I sent the manufacturer a demand letter. They were non-responsive so I then hired an attorney to also send a demand letter. After that I filed an arbitration request through the AG’s office. Now Mercedes is in the process of repurchasing the vehicle. They hired a third party to handle the repurchase and we should have the matter closed out by mid-February, four months after we started the process.
In our car the problem appears to be in the battery cooling system, because it seems to only occur when driving in all-electric mode. We took the car on a two thousand mile road trip, running on the gas engine the whole time and not a single fault ever happened. When we got home and plugged the charger in for local driving in electric mode it faulted again three days later.
The dealer has replaced the battery cooling pump, the battery coolant sensor, repaired a cold solder joint on the wiring harness, updated the software for one of the engine computers, replaced the engine wiring harness, and replaced the battery coolant controller. Still no success in eliminating the problem.
The dealer has replaced the battery cooling pump, the battery coolant sensor, repaired a cold solder joint on the wiring harness, updated the software for one of the engine computers, replaced the engine wiring harness, and replaced the battery coolant controller. Still no success in eliminating the problem.
Hi just wanted to check in to see how it’s going. I was told by the dealer that Germany still doesn’t have a fix for my car‘s coolant sensor issue but that it is safe to drive, so I need to pick it up. It’s been there 2 weeks on this round. Apparently, the check engine light will keep coming on, and I am supposed to ignore it. I can’t believe I pay this much for a lease on a car with so many issues. It sounds like I need to research lemon laws in california!
I'd wonder about the potential for further consequential damage that may occur if there was a coolant issue and you were driving it around and ignoring the indication on the advice of the dealer. We were in that situation early on-the dealer's shop told my wife to continue driving the vehicle in spite of the warning indication. A mile after she started up there was a red coolant indicator showing on the dash, plus a couple fault codes. That's when we dropped it off and told them to call us when it was fixed.
It may be worth your while to hit the dealer up for a loaner until they resolve the problem. Ours was pretty good about providing one for all our service calls.
It may be worth your while to hit the dealer up for a loaner until they resolve the problem. Ours was pretty good about providing one for all our service calls.
Hi, I'm from Korea and we are facing the same problems as well. Hundreds of people are sick and tired of this problem, where the Mercedes group has no clue how to fix the problem for the moment. What's more to this coolant warning signal is that we have incidents of the car showing a red alert signal saying immediately to stop the engine. I assume vehicles with M274 Engine are having these kinds of problem. The issue should be raised globally so that the Mercedes group should realise the seriousness of the problem. We can't just ignore this issue, we did not pay for this! Hope everyone gets alert on this issue!
What is the m274 engine?Hi, I'm from Korea and we are facing the same problems as well. Hundreds of people are sick and tired of this problem, where the Mercedes group has no clue how to fix the problem for the moment. What's more to this coolant warning signal is that we have incidents of the car showing a red alert signal saying immediately to stop the engine. I assume vehicles with M274 Engine are having these kinds of problem. The issue should be raised globally so that the Mercedes group should realise the seriousness of the problem. We can't just ignore this issue, we did not pay for this! Hope everyone gets alert on this issue!
Not a check engine light but a coolant symbol. View attachment 3509
One of the attempted repairs was a software update which didn’t resolve the problem.
We’re turning the car in as a lemon. It’s a great driving car but I don’t want to be stuck with this when the warranty expires, especially if it’s so difficult to identify the root cause of the problem.
Our 2020 GLC has had two problems this week: Hot coolant warning first. Towed to dealer who installed a new water pump. 50 miles later we got the thermometer icon. Five hours later at a different dealer they have no idea. Using the loaner car now and contemplating the Lemon Law if this keeps happening.What is the m274 engine?
I just completed the buyback process. It was pretty straightforward, but it took several months. You have to research your state‘s lemon laws to know how many times the car has to be seen for the same issue to qualify.
We are having the same issue however this time my car completely died and nearly caught fire. I am hoping to get some resolution from our local dealer. This is unacceptable and quite scary. If anyone has any advise, please let me know!We purchased a new GLC350e last summer and have had chronic cooling issues ever since. Wondering if anyone else has seen similar problems.
When running on the battery we often get a cooling system fault light on the dash display. We’ve had the car in for service 7(!) times now and they’ve not been able to identify the source of the problem, much less repair it. I don’t see references to this sort of issue on this forum, so perhaps not a common occurrence?
Anyone heard of this sort of problem before?
So far the dealer has replaced one of the motor/pump assemblies, a temperature sensor, the controller for the coolant at the battery, the engine wiring harness, upgraded the software for the engine computer, and repaired a connection on the wiring harness. The problem is still there.
As much as the wife loves the car, we’re at the point of turning it back in as a lemon. If the dealer, the corporate office, and the factory all working together can’t properly diagnose and repair a problem than I don’t want to be on the hook for figuring out what it is when the warranty runs out.
1 - 13 of 13 Posts
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