weird EML fault

Strange one....
Since yesterday the engine management light is coming on in a weird pattern.

From cold it lights up and stays lit until there is a bit of heat in the motor, then it will light up at anything BELOW 1900rpm and goes out when revs are above this. This happens either under load or revving freely at a stand-still.

No reduction in power or any other symptoms - it runs as well as ever.

Gradually, the rpm level at which it comes on and off will drop down to about 1500, then 1200 rpm and then if I decelerate right down in a high gear it will stay out for a while, then start coming on as before after a few miles.

its a 2001 td4 with recon injectors, recent turbo, disabled EGR, synergy 2a and pierburg MAF which has been fitted for maybe a couple of years without issue.
fluid levels are fine, electrical connections all seem fine, hoses all seem fine.
Any clues?

I think you should get the codes read.

Whatever is causing the LIGHT to come on, will leave an error code.


It could be almost anything, and a guess is only that - a guess. I'd say a non critical sensor is going out of spec and especially so when cold, but that is a total flippin GUESS.

Meh, its cured itself so I will pat myself on the back and call it a job well done.