Adblue countdown Mercedes C Class

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Djw11

New Member
Joined
Mar 23, 2023
Messages
1
Location
Warrington
Car
Mercedes C220 Estate
I thought I would post this as I saw when I was having problems there were lots of posts about Adblue and this may help.
Just before Christmas my EML came on, it showed that it couldn’t read my Adblue tank ( which had plenty in) and then the dreaded Adblue countdown began, saying that I wouldn’t be able to start my car in 480 miles. I only do a very low number of miles these days and it had been incredibly cold so I wondered if the Adblue could have crystallised due to the temperature. I read somewhere that if you battery is low it can cause problems so I did two things. Firstly I charged my battery up to full and secondly got some Forte AdBlue Tank Exhaust Crystal Preventer. I got COVID so it was a few days before I went back to my car, when I did the countdown had gone, it was showing 12,800 miles of Adblue and on the second start after going into town the EML went off.
When I got the chance I went to my local garage who put the car on an OBD ( not a Merc specialist). It shown a stored code which was non specific as problems with Adblue system. Over the next few weeks, the countdown didn’t come on but the EML did and it was showing unable to read the Adblue. Each time this happened I charged the battery and after a couple of starts in went off. So I invested in a new battery which brought my Stop/Start back to life.
I was going to Wales on holiday so the next time the light came on I tried the OBD again. This time it showed P2047 Reductant Injector Circuit/ Open Bank Unit 1. After doing a bit of research on the internet I came to the conclusion that it may be the Adblue injector, so I asked the local garage to clean it which he did. It was full of crystallised Adblue. The car was fine for about a month then on the second day of my holiday in Wales I was back to square 1. Countdown back on at 483 miles, EML and unable to read Adblue.
I found a local Independent Mercedes Specialist nearby and was lucky enough to get in on the next to last day of my holiday. they looked at the injector but it was still clean from when my local garage had it. They put it on their computer and whilst they were able to reset it because it switched between full and unable to read Adblue, the Countdown went off before going on back at 500 miles. They said they believed it was a broken wire but as I was going home the next day there wasn’t enough time to search for it. They charged me £99, which I thought was reasonable. When I got back I took the car to my local garage, who is also my friend, he was busy but as I didn’t need my car he looked for the broken wire in between jobs. He couldn’t find anything having looked at the appropriate wires. I had been researching and found this guy
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. Whilst it was a Sprinter and not a C Class the problem seemed the same. My friend and I agreed that the injector was the most likely problem so I bit the bullet and asked him to get me a new one and fit it. ( You don’t need any Mercedes specific equipment to do this, they just swap over and driving it for about 50 miles does the trick.) he got the new one from Mercedes for £440. There we’re cheaper ones on EBAY but I thought the proper part would be best. Countdown and EML have now gone and it is reading the correct amount of Adblue.
Hope this helps someone with this problem.
 
I thought I would post this as I saw when I was having problems there were lots of posts about Adblue and this may help.
Just before Christmas my EML came on, it showed that it couldn’t read my Adblue tank ( which had plenty in) and then the dreaded Adblue countdown began, saying that I wouldn’t be able to start my car in 480 miles. I only do a very low number of miles these days and it had been incredibly cold so I wondered if the Adblue could have crystallised due to the temperature. I read somewhere that if you battery is low it can cause problems so I did two things. Firstly I charged my battery up to full and secondly got some Forte AdBlue Tank Exhaust Crystal Preventer. I got COVID so it was a few days before I went back to my car, when I did the countdown had gone, it was showing 12,800 miles of Adblue and on the second start after going into town the EML went off.
When I got the chance I went to my local garage who put the car on an OBD ( not a Merc specialist). It shown a stored code which was non specific as problems with Adblue system. Over the next few weeks, the countdown didn’t come on but the EML did and it was showing unable to read the Adblue. Each time this happened I charged the battery and after a couple of starts in went off. So I invested in a new battery which brought my Stop/Start back to life.
I was going to Wales on holiday so the next time the light came on I tried the OBD again. This time it showed P2047 Reductant Injector Circuit/ Open Bank Unit 1. After doing a bit of research on the internet I came to the conclusion that it may be the Adblue injector, so I asked the local garage to clean it which he did. It was full of crystallised Adblue. The car was fine for about a month then on the second day of my holiday in Wales I was back to square 1. Countdown back on at 483 miles, EML and unable to read Adblue.
I found a local Independent Mercedes Specialist nearby and was lucky enough to get in on the next to last day of my holiday. they looked at the injector but it was still clean from when my local garage had it. They put it on their computer and whilst they were able to reset it because it switched between full and unable to read Adblue, the Countdown went off before going on back at 500 miles. They said they believed it was a broken wire but as I was going home the next day there wasn’t enough time to search for it. They charged me £99, which I thought was reasonable. When I got back I took the car to my local garage, who is also my friend, he was busy but as I didn’t need my car he looked for the broken wire in between jobs. He couldn’t find anything having looked at the appropriate wires. I had been researching and found this guy
To view this content we will need your consent to set third party cookies.
For more detailed information, see our cookies page.
. Whilst it was a Sprinter and not a C Class the problem seemed the same. My friend and I agreed that the injector was the most likely problem so I bit the bullet and asked him to get me a new one and fit it. ( You don’t need any Mercedes specific equipment to do this, they just swap over and driving it for about 50 miles does the trick.) he got the new one from Mercedes for £440. There we’re cheaper ones on EBAY but I thought the proper part would be best. Countdown and EML have now gone and it is reading the correct amount of Adblue.
Hope this helps someone with this problem.

Any problems with mine ,it'll get mapped from the ECU . You can guarantee if one part has failed ,more will follow.
 

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