AdBlue countdown timer

[S350L]

Hi all

I took my w221 s class to my local dealer with the engine light on again. They’ve already replaced the egr valve and a map sensor hose on my last 2 visits in the last 3 weeks, without extinguishing the engine light. There were no messages on the dash. After 6 hours, I get a call to say that the NoX sensor has now failed and that the adblue system is shutting down, with 400 miles left on the countdown timer. Merced’s said it needs a new NoX sensor, which may cure the AdBlue situation.

When I got my car back, there is a warning on the dash (which wasn’t there before), saying ADBLUE, eng start not possible.

When should the AdBlue countdown warning appear and how many miles does the countdown start?

I plugged in my basic code reader and “cleared” the engine light and codes, then drove the car for about 5 miles without the engine light or AdBlue warning coming back on.

Any ideas??

Many thanks in advance

 

[tode]

Hi,

Is the Adblue tank full ?

 

[S350L]

Hi,

Is the Adblue tank full ?

Thanks for the reply, about half way I reckon

 

[S350L]

In the last month mercedes have fitted a new egr valve, map sensor hose and ate now telling me that it needs a NoX sensor and possibly something in the adblue system.

As anyone else had these or similar fail at the same time? Do these components all go through the same control unit and could that be at fault?

Again, thanks in advance

 

[rf065]

Not sure if this is 100% correct, but if you run out of adblue or the system is faulty, I think you can get home, maybe this was the 400 mile warning. After stopping the engine, it will not start again until the original fault is fixed. If adblue has run out, putting a litre in will not help, it needs quite a few litres before it will allow the engine to start. Not sure how other faults affect it though.

Russ

 

[S350L]

Thank you for your reply

Just to confirm that the car has never run out of adblue

 

[rf065]

Thank you for your reply

Just to confirm that the car has never run out of adblue

I realised that, bit I think the system works on the same principal whether you run out or have another fault.

Russ