E46 M3 'DME'...help

[nutcase]

Car has been playing up over the last week- triggering the emission warning light, which prevents you using over 4k RPM- so I took it to Vines in Guildford and they thought they'd cured it a couple of days ago, got it half a mile and the warning light came on again... not good. So, a couple of hours investigating the car today and they can't seem to find out what the problem is- so they're going to try a new DME (basically the ECU as far as I can tell from Google etc) from another M3 they've currently got in. If it is the ECU which has a problem, it could be something like 1000 quid to buy- which isn't inconsiderable on a car worth probably 16000 now!

Any advice people other than wait to hear what they say? (i'm wondering whether it might be an option to go down the route of remap, unless of course it's physically a problem with the existing ECU and software won't help)...

I blame it on the fact I was on here singing it's praises last week as a brilliant everyday car thread...sod's law.




(Edited for spelling)

Edited by nutcase on Tuesday 2nd October 15:51

[robbyt]

Lambda sensor or engine ecu temp sensor???

[ism123]

Vanos? Had a similar problem with mine a while back. Though it would rev past 4k it sounded rough and the DME light was on. They should pick that up on the diagnostics.

[nutcase]

Yeah, they did mention that they'd tested some sensors and just that they'd see how it goes today when they test with the alternative ECU...

Will report back later on the 'fix'

[nutcase]

Apparently it's an Oxygen sensor, still a bill of 500 quid but not as bad as a new ECU!...