how to fix Mercedes engine start not possible fault. Once you have seen the engine start not possible displayed on your dash you may think you have a huge bill ahead of you.
The first solution – Simple
Normally you will have had a count down displaying the number of engine starts avalible. If like most people you have ignored these you may want to add at least 3 liters of adblue to your adblue tank. Turn you vehicle off and then top up the adblue tank with at least 3 liters of adblue. It has been know to just top this up with diesel but we do not recommend topping you adblue tank up with diesel. Only use the recommend adblue to be safe.
Solution number two – specialist or dealer
if topping your mercedes adblue tank up has not worked you will either require a mercedes specialist or a mercedes main dealer equiped with mercedes star / Xentry to perform the latest software update.
You may or may not be aware that there is an update for mercedes adblue that directly affects the software calibration relating to mercedes adblue and the fault that causes the “engine start not possible” message on the dash.
You should check to see if you vehicle has had this update, as it will be free (known issue) if you have visited mercedes for a service or any other type of mechanical / warranty work. IF NOT you may have to pay to have the update.
Next up N0X sensor failure
Failing this the next cause is the N0X SENSOR this N0X sensor is again directly related to the amount of adblue that is injected, if you have tried the other options this is you last resort. The N0X sensors for mercedes diesels range from around 350 to over 600 gbp. You would also expect to pay upto one hour of mechanical labour.