Code 42 Fix

Ok had code 42 speed sensor prob .flashing o/d light ,warning triangle,and engine shaped light top right {mil light}

FIX:Take off the top part of dash and remove multi-plugs .On the one that goes into the odo you will see a pink wire and a blue/ red wire. r/h side of plug. join the pink wire from the multi plug to the red/blue wire , and the other end of the pink wire that comes from behind the dash just blank off .

just took her for a blast and woohoo no more flashing lights.

and this actually cures the problem properly?

I have a 1993 J-spec N/A showing the same error code. (only bought it today and dont know where anything is yet!)

Which bit of dash needs removing? Pics would help hehe!

I'd like more info on this too.

Cheers

Yes please. More info. Mines been doing the same for about 6 months now and it's really starting to annoy me. Already changed the delimiter chip once so reluctant to do it again if i don't have to. How did you come across this solution btw?

I can confirm what Dave says, I did this fix a few weeks ago, did 148mph on the way to the Le Mans 24 hours and .............................no lights !!!

Yes it does work, have had to do it on loads - But only if its due to a deliminter being installed.

If you have a faulty No.1 speed sensor or speedo or a short in the wiring it wont fix it

My traction control is faulty too. Front left and front right speed sensors apparently. Is one of these the no 1 speed sensor? If so then quick fix probably wont fix.

Yes it does work, have had to do it on loads - But only if its due to a deliminter being installed.

If you have a faulty No.1 speed sensor or speedo or a short in the wiring it wont fix it

Mine is still limited to 112mph does that mean that this fix won't work?

What is it likely to be if not and how might I fix it?

Don't fancy taking it to mr Ts for a nice £200 per hour mess about if its something I can have a play with.

What does this fix...can anymore describe the symptoms.

Error code 42 I hope.

On mine I get the warning triangle and the orange engine warning light on the display to the rh side of the steering wheel.

It happens when I boot it, have been playing with it lately trying to get it to go off by doing certain things to kind of narrow it down a bit.

On a boiling hot day it never happens, no matter how hard I drive it. On a cool day or in the evenings the warnings seem to come on when the second turbo starts working.

Thought it was only when i hammer the car but the other day i tried putting my foot about half way down and allowing it to climb up the rev counter slowly, three times the warnings came on just as the second turbo comes on.

If I gun it hard and the warning lights come on then they stay on for ages, if I let it creep up slowly then the light comes on for only a few seconds.

Its weird coz it doesn't always come on!!!!!!

Anyone got any ideas???

There's loads of threads about code 42: I've written one or two myself!

It's VERY likely to be an electrical fault, rather than the speed sensor itself. The odometer unit buffers the speed signal it gets from the speed sensor, and then chucks it back out to the ECU. This buffering can often go wrong due to dodgy soldering etc on the odo. Joining these two wires together *I think* joins the input to the output, therefore no buffering. No-one seems to know why it buffers: bypassing the buffering doesn't seem to cause any problems.

I had the same symptoms when i fitted a speed delimeter chip. Tried a couple of different chips and eventually removed chips completely i.e. took car back to standard running KPH and limited! Still got the same problem - flashing O/D light (constant), red triangle and engine management light come on about 80 MPH (or the equivalent KPH) reading on the TDR speedo!

Some pics of the fix (wires before and after) would be much appreciated.

I'm getting the code but i don't have a delimiter fitted or anything like that, completely standard as from the factory.

Will this solve my problem?

Yep i did this too, Works fine

Well you could give it a try in case its a fault in the buffer circuit, if it dosnt cure it then its one of the Code 42 problems outlined

I had the same symptoms when i fitted a speed delimeter chip. Tried a couple of different chips and eventually removed chips completely i.e. took car back to standard running KPH and limited! Still got the same problem - flashing O/D light (constant), red triangle and engine management light come on about 80 MPH (or the equivalent KPH) reading on the TDR speedo!

 

Some pics of the fix (wires before and after) would be much appreciated.

And do the lights go off when you slow down to 20mph or less?

i have this problem joined the two wires together behind the odo and problem still there. constant od and slip control flashing abs not working engine management light comes on and the red triangle.

car still in kph still limeted to 185kph just getting really confused now what else could this be please

And do the lights go off when you slow down to 20mph or less?

No once they come on they stay on until I switch off and restart car.

No once they come on they stay on until I switch off and restart car.

Interesting.

And approximately at what speed do the lights come on? 50-60-70mph

I have noticed mine come on at 55-60mph (when accelerating reasonably hard) and then when I reach 85-90 they go off. And when I slow down to 20 or to a standstill the lights ALWAYS go off.

This doesnt happen everytime though...only sometimes.

my o/d off light is intermitten, but almost always comes on after WOT for 6-8 seconds or anytime over 100kph.

Interesting.

 

And approximately at what speed do the lights come on? 50-60-70mph

 

I have noticed mine come on at 55-60mph (when accelerating reasonably hard) and then when I reach 85-90 they go off. And when I slow down to 20 or to a standstill the lights ALWAYS go off.

 

This doesnt happen everytime though...only sometimes.

Around about the 80mph mark

mine was coming on at 4k revs and going off at 100 leptons + mine is cured now hasnt come on since ,

you need to remove the top part of the dash with the odo and warning lights

5 screws unclip the the multi plugs both sides and put the piece to one side.

the multi plug that goes in the odo you will see on the right side as you look at it a pink wire next to that is a blue/red wire.cut the pink wire about an inch from the plug same with the blue/red wire now join the pink wire from the multi plug to both ends of the blu/red wire splice it in. the pink wire that comes up from the inside of the dash just blank off this bypasses the speed sensor and stops your lights flashing. odo still works if anyone wants pics will get it apart on sunday.make sure it is code 42 speed sensor that is triggering your warning lights first.

Is this one of the "de-restrict and convert a J-spec" issues?

dude, does doing this effect the speed sensitive steer and speed-sensitive front spoiler? Surely, it would as they both get there speed input from this wire. I'd really like to find the real problem and fix it rather than do a work around.

try this thread http://www.mkivsupra.net/vbb/showthread.php?t=35920 again make sure its code 42 you have