CEL reset E220Cdi, W211.206, OM646.961

[mejermy]

Whilst fitting my EGR delete circuit this morning I inadvertently tried to switch on whilst the relay box 'M' connector plug was out. Result CEL light. There's no issues with the car and the EGR shunt seems to work fine, but I think there is a transient fault logged as a result of my error. Does the CEL extinguish itself after a certain time if there is no ongoing fault?

 

[Dieselman]

Let the engine run a few cold to hot cycles and see if the light goes out.

 

[sportscars]

all else fails disconnect the battery for 10 mins and re connect

 

[Dieselman]

all else fails disconnect the battery for 10 mins and re connect

I would put money on that doing precisely nothing.

 

[mejermy]

Disinclined to do anything until I've run her through a number of starts. DM's observation is interesting implying cold starts only. As you will be aware, this car has an auxiliary battery due to having more electrickery than battersea power station (used to), so I fear that a disconnection may leave the memory powered up. I want to avoid resets everywhere as well. Thought someone might have an idea of the number of cycles though. There was a time when the handbooks were just a few pages thick, but actually told you what you wanted to know. Now however..............

 

[mejermy]

Couldn't be bothered to wait for the CEL to extinguish after a certain number of starts (if it ever does - information on this scant) so bought a U480 scan device for pennies. Super piece of kit; cleared the codes set by my earlier incompetence and none have returned, so another succesful EGR shunt mod.