Warning light around 100mph

I'm unsure what the problem is, I have used the search but with no avail,

around 100mph I get the main warning light up and stay on until I have turned the car off the light does not appear until I get to around 100 again,

I have tried error codes but light flashes constant so no codes are stored, My first thought was it maybe over boosting but the car is standard apart from hks bov, and a 3.5'' cat back exhaust, I'm waiting for a boost guage to come through the post

the car feels fine when the light on but I have no idea what it maybe,

cheers for any help in advance

Do you have an SLD fitted?

overboosting would result in a fuel cut and you would definately describe that differently quite violent - also, the check engine shows up and turns off again.

No other lights? Have you checked if some might not be working? I'm thinking of brake fluid level might be it? (although it doesn't make any sense regading the 100mph.

Does it only show itself @ WOT? (since you though of it being over boost)

shot in the dark, but I understand that some of the cheaper top speed delimiters (TSD) will 'rollover' at 100mph, so teh ECU thinks the car is doing 0mph (not 100mph). Clearly that doesn't add up when other sensors are telling it you can't be stationary, so you can get an error. I had similar when I'd only half plumbed-in a speedo convertor/TSD and got up to about 60mph. When I'd finished installing it and all speed related sensors were seeing the same signals it never happened again.

edit - Top Speed Delimiter (TSP) AKA Speed Limit Defender (SLD)

Mine does a similar thing and i have put it down to the SLD

There must be a sld as I had the car to 130 to see if it was resticed still, which doing that it must have sld, my thought of overboost because the 1st time it cam on at 115ish then the second time it came on was when I backed off at 90,

I thought overboost because of revs, gear and speed, revs are over 5000rpm so one would assume turbos are at full boost or overboosting, but fuel cut does not happen which is one reason I can't work out what the problem could be

Did your car ever have an active spoiler?

I'm unsure it has the loom for the spoiler as the button lights up, when auto spoiler is pressed but I had it turned off ever since I got the car, would like to fit an active spoiler but I want a fmic in the future, so i'm in two minds to have one or not

I removed my active spoiler motor and lip and as long as I had it turned "off" I never had a problem. If it was turned "on" the ! light would illuminate at ~100mph.

I have now removed the switches from the car (so can't turn it off) and I get the main "!" light coming on at ~100mph again. Apparently two pins of the spoiler loom can be linked up to prevent the light coming on.

It should actually light up at something like 60 or 65mph but the wiring of my SLD must be wrong meaning it comes on at 60 / 5 x 8 = 96mph.

So, if your's is like mine, you have two problems....an SLD wiring issue and an active spoiler warning light for a spoiler deployment failure

i have the same issue,

im guessing you have a J spec car.

as they are usually restricted to 110mph, they throw a warning if you go over that.

here was my thread

http://www.mkivsupra.net/vbb/showthread.php?t=210386