View Full Version : 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.:d
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!
MarkTheBoy
10-07-06, 20:50
:bump:
I'd like more info on this too.
Cheers
Ruff_Rider
10-07-06, 23:16
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
Ruff_Rider
11-07-06, 18:41
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.
MarkTheBoy
12-07-06, 21:36
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.
MarkTheBoy
12-07-06, 22:01
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??? :sos:
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?
CardiffSupra
13-07-06, 16:38
Yep i did this too, Works fine :D
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.
Jspec Germany
14-07-06, 11:29
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.
Need4Speed
14-07-06, 22:45
Is this one of the "de-restrict and convert a J-spec" issues?
Jspec Germany
15-07-06, 07:41
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
Does this point to a dodgy odometer?
i think its normally with de-restricted whatsits
My car is back to standard (jap spec)...no delimeter chips, etc. and I'm getting this code 42. If a dodgy odo I'd rather try and replace it to sort it once and for all.
My senser is also coming on at random and stays on until i SWITCH THE CAR OFF. i'M GONNA DO A CODE ERROR CHECK TOMORROW and hopefully get to the bottom of this once and for all...
Looks like my issue is more linked to revs rather than speed!
Hi guys,
Yes, code 42 is often due to a dodgy odometer. I think the soldering goes dry on the odo circuit board or something. Dry solders can be very hard to trace! There are other things that can cause code 42, but this is the main one. If it's a dodgy odometer, new ones are very expensive from Mr T (several hundred pounds I think).
You can get a second-hand one, but 1) who knows when the soldering will go dry, and 2) until someone can sell you one, you'll be driving around in a car who's engine warning light will be lit 80% of the time.
When my odo did this, I bought a converter/TSD from Thor, and in the fitting instructions is how to bypass the odo's speed buffering. Bypassing the buffering doesn't seem to have an adverse effect on the progressive power steering (i.e. still works as it should do).
Hi guys,
When my odo did this, I bought a converter/TSD from Thor, and in the fitting instructions is how to bypass the odo's speed buffering. Bypassing the buffering doesn't seem to have an adverse effect on the progressive power steering (i.e. still works as it should do).
hey steve, can you post those bypass instructions...?
Can I *bump* this for any updates from anyone or on the Thor bypass instuctions please.
Shaun.
Im all confused now. I thought that a flashing o/d light was the speed sensor fault, or is this another problem. As mine was doing this for the first time the other day then its gone off again.
Whats it all about.
Try this link guys:
http://homepage.ntlworld.com/peter.betts/supra/TechTips/speedo.htm
Hodge: a bit of background for you. The electronics in the supra's odometer unit can play up sometimes, and the symptoms you get when it does this is a speed sensor error (code 42). However, this is only the ECU's interpretation of what the problem is. In my experience, the speed sensors themselves very rarely need changing, and the problem usually lies in the odo.
Try this link guys:
http://homepage.ntlworld.com/peter.betts/supra/TechTips/speedo.htm
Hodge: a bit of background for you. The electronics in the supra's odometer unit can play up sometimes, and the symptoms you get when it does this is a speed sensor error (code 42). However, this is only the ECU's interpretation of what the problem is. In my experience, the speed sensors themselves very rarely need changing, and the problem usually lies in the odo.
stevie, thx for the link, where is the section about bypassing the buffering of the odo?
Jspec Germany
27-08-06, 06:13
Yeah, I didn't find it either. I think I have a dodgy odometer. My car needs to stay in kms and I am only using the delimiting function so I just want to fix/mod the odometer.
Yeah, sorry guys! The linked page doesn't really explain what to do. Click on the link labelled "Here's the schematic" to bring up a circuit diagram of the plugs and wires of the speedo system. I'm 90% sure that the "speed signal input" pin on the odometer plug is pin 5, and the output pin is pin 6 (i.e. the re-transmitted buffered signal).
If I'm correct, what you'll need to do is strip some of the insulation on the pin 5 wire, cut the wire to pin 6, and solder the loom side of the "pin 6 cut" to the exposed pin 5 wire. This merely bypasses the buffering of the odo unit.
This is from looking at the diagram on the web: I'm fairly certain of what I've written, but I'll try and dig up a diagram at home to confirm it. If I don't post on this thread again in the next couple of days, please remind me!
Steve
Jspec Germany
29-08-06, 10:40
awesome dude.. please let me know. can anyone else confirm?
Yeah, sorry guys! The linked page doesn't really explain what to do. Click on the link labelled "Here's the schematic" to bring up a circuit diagram of the plugs and wires of the speedo system. I'm 90% sure that the "speed signal input" pin on the odometer plug is pin 5, and the output pin is pin 6 (i.e. the re-transmitted buffered signal).
If I'm correct, what you'll need to do is strip some of the insulation on the pin 5 wire, cut the wire to pin 6, and solder the loom side of the "pin 6 cut" to the exposed pin 5 wire. This merely bypasses the buffering of the odo unit.
This is from looking at the diagram on the web: I'm fairly certain of what I've written, but I'll try and dig up a diagram at home to confirm it. If I don't post on this thread again in the next couple of days, please remind me!
Steve
the pink wire is the speed sensor wire in the blue/red wire is the out{ 99% sure} i joined the pink wire from the loom side to the blue/red and my speedo was all over the place .then cut the pink wire you have two bits one from loom one from multi plug. tape off the loom side and join the bit coming from the multi plug to the blue/red wire in the next pin. cant post any pics cause i taped it all up. and no probs since
according to this diagram the pink wire from the multi plug {odo} is not joined to anything am i right and the loom side pink wire is attached to the BLUEWIRE is this diagram just the normal wiring for a delimiter or does it include the code 42 fix ???????? im confused now:(
as ive now developed a new problem with the speedo going on/off if i tap the odo case it comes back on ive either got a dry joint or my odo is foooked
Im all confused now. I thought that a flashing o/d light was the speed sensor fault, or is this another problem. As mine was doing this for the first time the other day then its gone off again.
Whats it all about.
yeah my o/d light was flashing too but not all the time this fixed that prob as well i think the three are all linked somehow
Yeah the problems are usually linked. The speed sensor sends the speed signal to the speedo dial, from there it goes to the odo, and from there it gets sent to the ECU which controls the progressive power steering, active spoiler, etc. If this sequence is broken at any point (usually on the odo circuit board), then the active spoiler, /o/d system and PPS will stop working properly. If your odo ticks up the miles or kms OK, then you can be sure that the speed signal reaches as far as the odo input
according to this diagram the pink wire from the multi plug {odo} is not joined to anything am i right and the loom side pink wire is attached to the BLUEWIRE is this diagram just the normal wiring for a delimiter or does it include the code 42 fix ???????? im confused now:(
as ive now developed a new problem with the speedo going on/off if i tap the odo case it comes back on ive either got a dry joint or my odo is foooked
That sounds right. The pink wire from odo plug (pin 6) is the output of the odo unit. If the odo's buffering is screwed, this wire won't carry a signal. So it's cut and an alternative signal (blue wire) is fed into it from the speed converter. Essentially, the diagram shows the output from the odo being discarded and instead an alternative speed signal (blue wire) is used.
However, sounds like you've got a dry solder there.
i joined the pink wire from the loom side to the blue/red and my speedo was all over the place
I think that's because you're trying to feed two signals to the ECU on the same wire, which it won't like. :) One signal from the odo output, and another from the odo input.
then cut the pink wire you have two bits one from loom one from multi plug. tape off the loom side and join the bit coming from the multi plug to the blue/red wire in the next pin. cant post any pics cause i taped it all up. and no probs since
Not sure how the odo gets the speed signal input if you've done that. It can only get it from pin 5, and that's been cut and joined on the loom side to the output. This would allow the ECU to get the correct speed signal, but does your odo still count up as you drive?
I think that's because you're trying to feed two signals to the ECU on the same wire, which it won't like. :) One signal from the odo output, and another from the odo input.
Not sure how the odo gets the speed signal input if you've done that. It can only get it from pin 5, and that's been cut and joined on the loom side to the output. This would allow the ECU to get the correct speed signal, but does your odo still count up as you drive?
it works fine with the mutli plug side of the pink wire connected to blue red wire-- doesnt this bypass the speed sensor no1
However, sounds like you've got a dry solder there.
thats what i thought just a gentle tap on the odo face brings it back up
ok this is the wiring excactly as i done it and it works
Well I'm really confused now. How can the PAS,Cruise Control and Active Spoiler work correctly when their signal wire (pink) is cut and not connected to anything?
I don't see how joining the pink to the input achieves anything if the pink is the output from the odometer.
Is there another output to the PAS, Cruise Control and Active Spoiler?
Well I'm really confused now. How can the PAS,Cruise Control and Active Spoiler work correctly when their signal wire (pink) is cut and not connected to anything?
I don't see how joining the pink to the input achieves anything if the pink is the output from the odometer.
Is there another output to the PAS, Cruise Control and Active Spoiler?
I agree. I'm glad that it works for you Dave, but I can't see how! :) I think the ECU, PPS, cruise control etc is all "downstream" from the wire that comes out of pin 6 (the pink wire in the diagrams), but this wire is left floating.
I haven't found the circuit diagram at home that confirms the input/output pins of the odo plug: will have a look in the next couple of days, but I'm pretty sure that I'm right about pins 5 and 6.
well i found this fix on here cant remeber where .but i havent got an active spoiler or cruise so i cant comment on how this would affect those systems .if you find any other way of doing it please let me know by PM. my steering seems to function ok havent noticed it going light at speeds
Jspec Germany
31-08-06, 10:42
You wouldn't notice it getting lighter because the PPS is already light at slower speeds. The question would be: Does it get heavier at speed as it should?
I definitely want to know whether or not the PPS and active spoiler still work with this pin 5/6 snip and fix.
Jspec Germany
13-10-06, 15:56
Has anybody made any headway on this issue? I am going to pull the dash tomorrow in hopes of fixing the code 42 and delimiting the car. If anyone has figured out how to fix/bypass the buffering signal to/from the odometer while keeping it functional, please chime in.
Sorry JSpec, I tried to find the documentation that came with my Thor DSC+TSD but couldn't find it.
so are we no further on with this, i agree if you do the fix it will solve the flashing lights problem as the ecu will not get the signal, however i think you will loose the active spoiler and pps and cruise control. is it worth doing that to just get rid of a light?
however when code 42 comes in does the ecu go to some sort of safe mode and shut them off anyway????
or is there another feed to the pps etc from another speed sensor?
I can't comment on the active spoiler or cruise control because I don't have them on my car. AFAIK the ECU only needs a speed signal from the odo unit in order to maintain the PPS. It doesn't matter if that signal is buffered by the odo unit first (i.e. stock wiring) or unbuffered (i.e. the modification that I suggested).
If it were me, I would do the modification to fix the code 42 problem. The engine warning light by itself isn't really a problem, but if the ECU logs another more serious fault, you'll be none the wiser because you'll either have pulled the bulb out of the warning light, or just be ignoring it anyway thinking "I can ignore that, it's just code 42".
I'm not aware that the ECU goes into a safe mode. I think it's up to the driver to respond to the warning.
The worst case is that the change I suggested doesn't work, in which case you could splice it back together. Not great, but it means that the change isn't totally irreversible.
Hope that helps a bit.
where does the ecu get its other signal for pps from mate? there isnt one on that diagram which was my point? :(
Sorry about that, I think this is what you need to do. Referring to the odometer plug, cut the wire to pin 6. This is the buffered output that isn't working any more. Strip some insulation from the wire to pin 5 (but no need to cut it), and solder the loom side of the pin 6 wire to it. This means that the speed signal flowing along the pin 5 wire will reach both the odo internals, AND be re-distributed to the PPS etc.
I think the PPS picks up its signal (possibly via the ECU which you shouldn't need to touch for this job) from the loom side of pin 6.
My PPS was overreactive and my odometer and blitz id meter werent working anymore. I did the trick as described above. It removed the warning light and it fixed my PPS. It works fine now. But my odometer isn;t counting, is there a way to solve that? :D
so what is the pin 5 wires function? if his odo isnt working is it the signal for that. if so its not a very good solution is it
My PPS was overreactive and my odometer and blitz id meter werent working anymore. I did the trick as described above. It removed the warning light and it fixed my PPS. It works fine now. But my odometer isn;t counting, is there a way to solve that? :D
Are you certain that you haven't cut the wire to pin 5? You should have stripped the insulation from the pin 5 wire (so that you can solder the pin 6 loom-side wire to it), but not cut it.
this is very confusing, some people say cut and splice from the plug side of the pink wire and some say as above to splice from the loom side????? whats the correct way??? i could fathom it if i knew the function of pin 5 (blue and red wire)
AFAIK pin 5 is the input signal to the odo unit, and pin 6 is the output. When you get a code 42, it's usually the output of the odo that has gone wrong, hence the need to NOT cut the pin 5 wire, and put the pin 5 wire's signal onto the downstream (loom-side) pin 6 wire.
yeah that sounds correct, but doesnt the odo bufffer the signal? if you re route the signal ie unbuffed it will still send out the same dodgy signal
Are you certain that you haven't cut the wire to pin 5? You should have stripped the insulation from the pin 5 wire (so that you can solder the pin 6 loom-side wire to it), but not cut it.
:blink: oeps
i have cut the pink wire and placed te loom-side of the pink wire to the blue/red wire
:blink: oeps
i have cut the pink wire and placed te loom-side of the pink wire to the blue/red wire
That sounds correct to me. The pink wire goes to pin 6 (hence the odo output) and the blue/red wire goes to pin 5 (hence the odo input). As long as you haven't cut the blue/red wire, I would have thought that would work OK. If it *still* doesn't work, then maybe we've got pin 5 and pin 6 the wrong way round. I've based my suggestions on the TRL diagram that appears on one of the posts in this thread, but there's a smaller diagram also in this thread that appears to suggest the input and output are the other way round. If that's the case, then I'll be as surprised as you are.
What this solution tries to do is to bypass a faulty buffering circuit within the odo unit. I have never seen an explanation as to why the odo buffers the signal at all. Most of the good TSD units you can buy actually bypass the buffer circuit themselves. I've bypassed mine when I had a code 42 a couple of years ago, and it has worked properly since then (including the odo display incrementing as it should).
Alan: it's the buffer circuit that's probably faulty, not the input signal to the odo. If you accept that there's no need for buffering (you'll either have to take my word on this, or not as the case may be! See above), then joining the loom-side output to the still-continuous input wire means that 1) the odo should still receive the input signal it needs in order to increment; 2) the rest of the car should receive the signal that it needs to properly control the PPS etc and to eliminate the code 42 error.
yeah this is the corrcet way to re route away from the buffer circuit within the odo. only thought i had was if the ecu still had code 42 if the signal was not buffed? trial and error i guess
I noticed my wires had been fettled with behind the odometer... now I know why. :)
I think that's because you're trying to feed two signals to the ECU on the same wire, which it won't like. :) One signal from the odo output, and another from the odo input.
Not sure how the odo gets the speed signal input if you've done that. It can only get it from pin 5, and that's been cut and joined on the loom side to the output. This would allow the ECU to get the correct speed signal, but does your odo still count up as you drive?
since i have done this i have had no problems everything works odo - speedo etc. and no flashing lights
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.
Mines now compeltely fixed by Mr Harwood and Thor. :D
Mines now compeltely fixed by Mr Harwood and Thor. :D
what did they do then imi???
Matt reinstalled it again, removed all the "scotch locks" and fitted another Thor converter.
Hi, hope this can be of some help to people. (It's already been mentioned above but hopefully this will clarify things)
I had lots of problems with my odo & speed sensitive steering etc. See this thread http://www.mkivsupra.net/vbb/showthread.php?t=89041
I tried Dave's Code 42 fix;
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.
This didn't work for me. I still got the warning lights & code 42 and the power steering stayed very light. :(
I joined the pink wire from the loom side to the blue/red and my speedo was all over the place.
After reading the above post i didn't bother trying this as i just assumed it wouldn't work and would mess up my speedo. After trying everything else possible i lost my rag, tried it, and now my car works perfectly fine. No error 42 and the progressive steering works fine, as it should. :D I was over the moon!
I'm not saying that Dave's way doesn't work (because it has for him) but i suggest trying both ways of wiring before moving on to something else! I wish i had! (it only takes a few minutes whereas re-soldering every part of the circuit board doesn't! netiher does removing your speed converter and re-fitting it! Doh! :rolleyes: )
Recap - The method that worked for me was joining the pink wire and the blue/red wire (behind the dash) and then only having the blue/red wire connected to the plug going into the odo. The pink wire going into the odo plug should be cut. This sends the speed signal straight to the ecu down the pink wire and the info needed for the odo goes in through the red/blue wire. (this has been mentioned by stevie b above ;) )
I have made a quick diagram in case my ramblings make no sense;
I just hope this helps people to fix the problem a lot quicker than i did! :D
If your odo ticks up the miles or kms OK, then you can be sure that the speed signal reaches as far as the odo input
I have a code 42 error im trying to track down at the moment. My MIL light comes on at 60mph, regardless of revs/boost. I have an active spoiler but its unplugged @ the AS ECU.
I've just wired in a replacement speed converter and still get code 42 @ 60mph.
My Odometer still increments the miles, so does this mean the speed sensor is OK and that the most likely culprit is the Odometer circuitry?
If thats the case I'll just see if JezzyBabes has a spare Odometer lying about.
Cheers
Simon
My Odometer still increments the miles, so does this mean the speed sensor is OK and that the most likely culprit is the Odometer circuitry?
Yep, sounds like it. If you're sure you've wired in the speed converter OK (and if the odo is incrementing, it sounds like you have), then a flaky odo unit is the most likely culprit.
i dont have a coverter on the car i do have one just not fitted yet would this still work 4 me
i dont have a coverter on the car i do have one just not fitted yet would this still work 4 me
Sorry mate, I don't understand you there. Could you re-phrase it please?
Just a quick update...after enduring this issue for almost two years took the car to Envy and they resolved it within a day!!! Wish I had gone there at the start.
Needless to say I would recommend anyone with the same problem to contact Envy to have it resolved.
Do you know what they did?
MarkTheBoy
27-05-07, 12:32
Where are envy based again? :search:
stevie b - took wiring back to stock and in the process found some duff wiring!
MarkTheBoy - 30 mins north of Newcastle. Check out the traders section.
Jspec Germany
28-05-07, 17:10
I can't just jump in the car and drive to Envy. Mine had the code 42 without the delimiter and I've apparently wired the TSD incorrectly because the car's still limited and the code 42 still there. Hopefully, I'll be able to fix it when I rewire.
JSpec: fixing the code 42 problem and wiring in a TSD are 2 separate jobs. Depending on the root cause of your code 42, I think some TSDs can fix the code 42 problem as a side-effect of installing them. I know my Thor TSD+DSC did. However, I realise that you don't want a DSC.
What make of TSD have you got?
If it were me (and apologies if you've already tried this), I'd remove any TSD you've got fitted, and simply bypass the odo buffering circuit (instructions around here somewhere on how to do this). Take it for a drive, and see if it fixes the code 42. If it doesn't, at least you know you need to look elsewhere (possibly the ECU connections). If it does, re-fit the TSD, making sure the fitting instructions don't re-instate the buffer circuit.
Some people don't like to chop into the wiring loom, but as long as you work neatly, any chops you make will be completely reversible with a bit more soldering and some electrical insulating tape.
Let us know how you get on.
Jspec Germany
29-05-07, 16:45
JSpec: fixing the code 42 problem and wiring in a TSD are 2 separate jobs. Depending on the root cause of your code 42, I think some TSDs can fix the code 42 problem as a side-effect of installing them. I know my Thor TSD+DSC did. However, I realise that you don't want a DSC.
What make of TSD have you got?
If it were me (and apologies if you've already tried this), I'd remove any TSD you've got fitted, and simply bypass the odo buffering circuit (instructions around here somewhere on how to do this). Take it for a drive, and see if it fixes the code 42. If it doesn't, at least you know you need to look elsewhere (possibly the ECU connections). If it does, re-fit the TSD, making sure the fitting instructions don't re-instate the buffer circuit.
Some people don't like to chop into the wiring loom, but as long as you work neatly, any chops you make will be completely reversible with a bit more soldering and some electrical insulating tape.
Let us know how you get on.
Ok Steve, thanks. I figured that was the case. I hear the most common culprit is dry solder joints on the odometer or the the output speed signal from the odometer being bad. Can't do it today, I had to fly and am already into the beer. :d
WAAAAAAAIIIIIIITTTTTT!!!! before you cut anything READ:
I've just completed this and happy to say my cruse is once again working!
BUT, there is no need to cut the pink wire, with a bit of fiddling round its not to hard to remove the pin from the harness and wedge it in the harness with the blue wire (for those of you who are perfectionists just use a glob of solder down there to hold it in firm and it will still be easy to remove later ). Don't stress to much if you break the pin as you should be able to get another one from dick smiths (radio shack?) or the likes.
i just used a tiny screwdriver (or a pin should even do it) squash the top of the end (the side that plugs into the ODO) of the pin in the harness and it should slide out.
If the end breaks you can crimp another end on later as long as you get it out
and DON'T forget to reset your ECU!
scratch that, over drive light is still flicking and code 42 is back, at least it fixed the cruise control not working issue..... must have another problem too.
after visually inspecting the odo it looks in decent condition.
any other ideas?
the unplugging the pink wire as ive said above still works though.. would rather do that than cut the wire.
Matt "Aero top"
17-06-07, 12:17
This is the fix i did and all my troubles went away
This is the fix i did and all my troubles went away
Sounds about right Matt. I think this is what I said in post #39, but you've said it a lot clearer than I did! ->
If I'm correct, what you'll need to do is strip some of the insulation on the pin 5 wire, cut the wire to pin 6, and solder the loom side of the "pin 6 cut" to the exposed pin 5 wire. This merely bypasses the buffering of the odo unit.
Jspec Germany
18-06-07, 20:55
Does that buffering do anything? Surely it has a purpose. Will my active spoiler still work? What about the speed sensitive power steering?
Does that buffering do anything? Surely it has a purpose. Will my active spoiler still work? What about the speed sensitive power steering?
When fitted correctly, the Thor DSC bypasses the buffer circuit. I don't think anyone's reported any problems caused by installing them. Can't really tell about long-term effects, but they seem unlikely to be caused by this sort of problem/fix.
Matt aero top's diagram joins what would be the buffer output (loom side) to the buffer input, whereas the Thor DSC supplies the buffer output (loom side) with a 1:1 (unbuffered unless the Thor unit duplicates the buffer circuit: unlikely) speed signal, and the buffer input is supplied with either a 1:1 signal (if you want the odo to keep counting in kms), or a 5:8 signal (if you want the odo to count in miles from now on).
The effect is the same for both changes: the odo buffer output is ignored by cutting the wire and leaving the plug-side unconnected, and supplying the loom-side with a signal derived directly from that supplied to the odo input.
I've got an NA so I can't comment on the TT stuff like active spoiler, but my progressive power steering works fine after fitting a Thor DSC.
Hard to believe I know, but I'm really not sure what useful purpose the buffer has. If anyone knows, please post it up here!
As I understand it a buffer usually duplicates a signal, but from a source that can supply more current. You only need a couple of resitors and an NPN transistor to make a simple buffer circuit.
Its possible that the Odo circuit does some pulse-shaping, too. I did ask a while back if anyone knew what the waveforms looked like pre- and post-buffer. If they are the same shape and don't cross the zero volts line then it might be very easy to make a stand-alone replacement buffer circuit.
Matt "Aero top"
19-06-07, 19:50
Does that buffering do anything? Surely it has a purpose. Will my active spoiler still work? What about the speed sensitive power steering?
the power steering the was one of the reasons i did this fix as mine was light all the time and playing up
Jspec Germany
19-06-07, 23:18
ok, thanks, gonna reinstall at the odometer/speedo.
I've done what Matt "Aero top"s diagram shows, however my overdrive light is still flashing, (cruise is fixed)
stevie_b you seem to know whats going on, any other ideas?
on why im still getting code 42 and the light still flashing, I even reset my ECU which fixed the issue until the drive after next.
I've done what Matt "Aero top"s diagram shows, however my overdrive light is still flashing, (cruise is fixed)
stevie_b you seem to know whats going on, any other ideas?
on why im still getting code 42 and the light still flashing, I even reset my ECU which fixed the issue until the drive after next.
Not sure TBH. Does your car have a Digital Speed Converter or a Top Speed Delimiter fitted? These can sometimes give up and cause a code 42, because anything that was getting the speed signal from the DSC or TSD would now not be getting anything. If it's not an imported car, then that's almost certainly a "no".
My car's got a manual gearbox so doesn't have the overdrive toys.
I would follow the flow of the speed signal: check if the speedo still works. Then check if the odo still counts up the miles/kms as you drive. Does your power steering get heavier (as it should) when you go over about 50mph?
It could be loose wires around the back of the speedo dial, or around the odo unit. It's possible that the odo unit has dry solder joints (the joints have been known to give up after 13 or so years of use). This can be hard to diagnose though.
Not sure TBH. Does your car have a Digital Speed Converter or a Top Speed Delimiter fitted? These can sometimes give up and cause a code 42, because anything that was getting the speed signal from the DSC or TSD would now not be getting anything. If it's not an imported car, then that's almost certainly a "no".
My car's got a manual gearbox so doesn't have the overdrive toys.
I would follow the flow of the speed signal: check if the speedo still works. Then check if the odo still counts up the miles/kms as you drive. Does your power steering get heavier (as it should) when you go over about 50mph?
It could be loose wires around the back of the speedo dial, or around the odo unit. It's possible that the odo unit has dry solder joints (the joints have been known to give up after 13 or so years of use). This can be hard to diagnose though.
not sure about the heavy... but the odo and speedo still work correctly I have the speed limiter removed by a SMT-6 piggyback chip.
Anyone know any more about this or found any more info on this?
I'm still flashing... :(
I still get this along with constant light/heavy steering. I'm off to try out Matt's fix. Will let you all know how i get on.
Okay, pulled the dash apart. My pink wire has been cut and instead of being joined to the red/blue wire it's connected to a white wire which then disappears behind the clocks. :blink:
Anybody know what this could be about? I don't want to cut anything I shouldnt be cutting.
Jspec Germany
09-09-07, 16:14
Sounds like you have a KMH-MPH converter or top speed delimiter wired in. It may have failed or be failing or could be a bad install. I still have to fix mine. I installed it incorrectly and haven't had the time to reinstall.
Okay, pulled the dash apart. My pink wire has been cut and instead of being joined to the red/blue wire it's connected to a white wire which then disappears behind the clocks. :blink:
Anybody know what this could be about? I don't want to cut anything I shouldnt be cutting.
Hi - I have inherited this problem as described by Chumpalot, when I bought his Supra a few months back.
I have had the speedo/odo part of the dash off to check the wiring, and here's a photo:
http://i247.photobucket.com/albums/gg132/jimmencio/odo_1.jpg
Now, I noticed a few soldered connections that had dodgy or no insulation at all. This may well be the source of the problem (overdrive lights flshing, speedo needle occasionally having spasms, power steering going light at speed etc.), but can anyone confirm that connecting the pink cable (loom side, that is spliced to the grey/white cable running to the delimiter/converter) and splicing into the blue/red wire (from pin 5) would effectively be the code 42 fix documented above?
I want to check, as no one yet mentioned their speedo/odo converter was wired into the pink pin 6 wire..
Cheers for any advice!
jimmenico,
It sounds and looks like you've already got a TSD/DSC fitted. If so, if the wiring looks OK (no loose wires other than the plug side of the pink wire), it's my guess that your converter is not working properly. Chances are that it's output is dead or very intermittent. The cheap ones don't last *that* long.
The fix you describe (join loom side of pink wire to pin 5) should only be done if you don't have a DSC fitted. The odo unit's buffer circuit has a habit of failing after 10 years or so (could be solder joints gone bad?), and this fix will join the circuit's input to the circuit's output, thereby bypassing the buffer completely, but this itself won't give you any speed conversion.
If I were you, I'd remove the DSC, reconnect the wires back to stock temporarily, and see if you still get code 42. If you do, the problem's most likely with the odo's buffer circuit (this can be cured with a correctly-wired good-quality DSC that supplies a signal to the loom-side pink wire, i.e. the grey wire in your photo). If code 42 goes away, your DSC is faulty (they're not generally fixable, better to buy a new one).
Hope that helps.
cheers for the info! I will have a play at the weekend and try and narrow down the failure...
Jspec Germany
08-02-08, 15:40
I need to do this this weekend as well. Been puting it off for way too long.
I have had this issue for a couple of weeks now, i will try to re-wire the fix in tonight :rolleyes:
:yahoo: Did the FIX tonight and it has been successful so a big thanks to Keron for all his hard work, Colin (Colsoop) for his help and encouragement and Stevie B for his advice and diagram :thumbs:
Gents this works :D:D
Sorry to drag this loverly thread up, but how did you get on jimmenico.
I have a TSD and DSC fitted that looks extacly the same as yours. Having the same problem (http://www.mkivsupra.net/vbb/showthread.php?t=146295) as yourself and was wondering hwat you may have done to get to the bottom of it?
Sorry to drag this loverly thread up, but how did you get on jimmenico.
I have a TSD and DSC fitted that looks extacly the same as yours. Having the same problem (http://www.mkivsupra.net/vbb/showthread.php?t=146295) as yourself and was wondering hwat you may have done to get to the bottom of it?
Well, I pulled the dash apart and found a few dodgy connections, which I tried to correct (or at least insulate!). To be honest, soldering would have been the best route, but unfortunately I didn't have the equipment available to me at the time.
Since playing with the wires however, the speedo hasn't been as erratic as it was. Instead, the speedo needle does nothing during the first 10 mins of driving and then starts working again...
I have now ordered a Thor DSC/TSD unit, so hopefully this will sort out the problem.
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