It's going to the dealer on wednesday, but I thought I'd check here to see if there are any simple reasons that this may turn it's self on (Engine Management Light that is).

It came on yesterday evening about 10-15 minutes after starting from cold. Coolant temperature was normal, oil temp gauge was still low. Was driving normally down a dual carriage way 50 in 6th nothing seemed to be the matter and then it just turned on with a beep. Nursed it home.

I've started it up in Diagnostic Mode and it doesn't have any DTC information - I don't have OBD II or anything, so there may be something code I can't see.

It sounds fine when running, it has plenty of fuel/oil/coolant. It's not leaking any fluids that I can see. It's been sitting in the garage all week and hasn't been driven since last sunday (until yesterday). Is it feeling lonely and in need of attention? Anybody any ideas?

 

lol yea its very very lonley it needs some of the good loving in the garage haha, my engine managment light came on ( on my rs focus ) and it turned out to be a couple of original rupper pipes leaking air apparently. it could be something really small

 

I have checked (read cursory glance) pipes and electrical connections - hopefully will turn out to be something like that... Just spent a load of cash on refurbing the wheels new tyres all round and 4 wheel alignment last week. I was almost happy with the car again!

 

Only very few DTC's show up on the dash test. My money is on a lambda sensor, very very common failure point on the st170. Take the negative lead off the battery for half an hour to reset the light and see if it comes back.

Rich

 

Yea lambada or coil pack.

 

Ok, so by all accounts I shouldn't be too worried about this. Thanks for the replies.

 

Don't dismiss it as a not so urgent fault. It could still be anything, and you won't get a proper diagnoses here.

 

indeed, but it isn't being driven anyhow except to take it to the dealer in a few days. So long as the engine isn't chewing itself up from the inside I'll be able to fix it with my credit-card shaped spanner.

 

And the culprit was HEGO/Lambda sensor

 

Thankfully that wasn't too bad, glad you got it sorted. Happy motoring.

 

Lucky you, the IMRC just blew on mine £200 just before xmas lol

 

 

Change the two Lambda sensor.
It's one of many black point of ST170...