[Mk2] [Turbo] Malfunction Light Issue...

[BrianUK]

Hi Guys - I have a problem with my '94 Rev 3 that is driving me crazy!...

I have just fitted a brand new 3GTSE engine. I have done 200 miles on it now and it purrs like you would expect a brand new engine to

My problem is that once I go past 50 mph , in 3rd, 4th or 5th gear, with lots of boost or with none - the malfunction light comes on.

Stop the car, restart it - or flick the ignition at under 50 and the light goes out.

I cant see any point in trying the diagnostics check because as soon as you stop the car and restart the malfunction light is out!!

There is no perfomance problem, the speedo is working - in fact apart from the malfunction light coming on I can find no problem???

What sensor on the car magically does something at 50 mph?

cheers - Brian

[Nic]

Even if the warning light goes out when you stop, the ECU will have the error code stored, a diagnostic check should help identify what the issue is.

[2tmike]

sometimes the codes are not stored....I get random engine warning lights on both an MR2 and a Celica just crusing down the motorway but nothing gets stored, and the cars are driving fine....
If yours comes on at 50 in all gears then it must (?) be speedo related somehow...if it's a turbo then I guess you have it delimited and a speedo kph to mph converter....maybe that installation is causing a problem in the wiring loom?

[Tsia]

IIRC, when Luke checked mine (same issue) I was getting error code 42, which means there's a problem with the speedo signal. That was right after a 3SGE->GTE conversion.

So yeah, likely something wrong with the converter. I assume you're not using an eBay one?

[BrianUK]

Aha! - brilliant - I didnt realise it stored the codes

Im getting error code 42 - which apparently is a speed sensor signal - since the speedo is actually working Im going to assume its the speed signal feedback to the ECU.

There is a KMH / MPH converter fitted (by a previous owner) which I assume is behind the speedo - as I cant see it anywhere else. Think I may just get a new one.....

Many thanks guys