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Code 42 Fix


Dave

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Guest Chumpalot

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.

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  • 4 months later...
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:

 

image

 

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!

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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.

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  • 1 month later...
  • 3 weeks later...
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 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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  • 3 years later...

Bumping an old thread but seemed the most appropriate.

 

I took all my dash apart today to clean them up and sort my error code 42 problem using the method in this thread.

 

I have a bit of a curve ball because my jspec has a speed converter in it. I tried googling the details but came up with nothing, firstly does anyone recognise this converter?

 

image

 

The wiring was pretty poor, pretty much bare wires just twisted together so suprised the converter worked. First thing I did was to redo the existing connections with choco block connectors.

 

image

 

I tested after each connection and things were good, I think I have knocked something as my speedo doesnt work at the moment but thats probably another thread (probably unhooked a wire) anyway the code 42 issue still remains.

 

Looking at my connector the pink wire had already been cut. Because of the converter the wiring is a little different. Currently the grey cable from the speed converter (ECU output) connects to the pink wire back from the connector. Does this sound right? I am trying to work out how to get it all sorted, interesting to read that some of this may relate to the overdrive issue on autos, so hoping I can resolve code 42 and OD issue if possible.

 

Probably needs more skilled eyes than mine at the moment. Has anyone got a Jspec with a coverter who would be willing to let me have a look at how theirs is setup or could lend me a hand or recommend someone who could look at it? Doesn't really seem a whifbitz or afr one I would say.

 

If you look at the pic below you can see the grey wire connecting to the pink wire in the background. Very greatful for any advice, getting very close to sorting these issues now :).

image

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Ok I have been spending some time on this again today. After following the speedo conversion guide and the schematic...

 

http://homepage.ntlworld.com/peter.betts/supra/TechTips/dsc_speedo_mph.jpg

 

I could see where I had gone wrong and got the speedo back working again. On my speed converter the grey cable which is marked ECU Output and is connected to the pink cable on the odo loom, I figured if I simply unhooked this it would effectively be the code 42 fix. Speedo worked fine still but as soon as I went over 60 I got the warning light indicating code 42 again. Anyone got any suggestions what I am doing wrong? at least I have proved the converter works even if it is not a fancy thor one.

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Looks like your DSC is made by Import Solutions: http://www.mkivsupra.net/vbb/showthread.php?107939-ODO-issues

 

Here's the equivalent wires between the TRL and CK-DU-99 DSCs:

 

TRL CK-DU-99

Red Red

Black Green

White Blue

Yellow n/a

Blue Grey

Green Yellow

 

I would think you'd need to connect the grey wire from the DSC back up to the pink loom-side wire (not the odo-side); that's probably a dead-end.

 

Does your odo count up OK when you drive? If it does, the speed signal must be getting lost between the odo output (pink wire in the loom) and the ECU's pin 2 (see TRL diagram).

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Thanks Stevie thats very helpful, I really appreciate it :)

 

I will check those connections over again tomorrow. I am a bit new to slicing apart these wires, when you say loom side are you saying that there is an equivilent 'pink wire' in one of the plugs that goes to the speedo cluster I should be tapping that ECU output wire from my converter into instead?

Currently it's where I found it going to the pink wire before the plug on the odometer connector.

 

attachment.php?attachmentid=47628&d=1164517403

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Referring to the TRL diagram, pin 6 of the odometer plug is an output pin, not an input. Connecting a modified signal to the odometer side of the pink cut won't work, as it won't go anywhere. It needs to be connected to the other side (the loom side) of the pink cut.

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I read through this thread briefly and since I've done this on a jspec, will comment. It did fix the error codes and warning lights as well as cruise control and the active front spoiler still work.

 

About the function of the buffer circuit in the ODO, I remember reading that it is indeed a signal shaper and trims the speed signal so that it isn't erradic. I've often wondered if going the more expensive route of getting a new odometer was a good option.

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ok, mines doing all of whats been mentioned in the thread , if i can live with the lights that come on , is there anything going to bugger up ?

 

Same here and I came up with the same conclustion, if it's not going to balls anything up I will live with code 42

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An unfixed code 42 error won't cause any harm, apart from 1) things like the Progressive Power Steering won't work as intended; and 2) if you get another error code logged by the ECU, you won't know about it as you'll dismiss the warnings lights as just being due to code 42.

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It would be much better to fix the underlying issue, if you can. Although a code 42 won't cause your pistons to part company with your crankshaft and punch 6 new holes in the bonnet, it will cause your power steering to be very over-assisted, and on TTs I think there are other issues (cruise control, active spoiler?). The fixes for code 42 are well-documented so you wouldn't be delving into the unknown.

 

But, if the above isn't possible then I'd recommend checking the error codes at regular intervals to make sure other codes haven't been logged. No need to reset the ECU, you just need to do the paperclip trick.

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Still got the problem afte I put it all back together and I could live with code 42 if it wasnt for the overdrive off problem which could well be related after searching the web. Where can I get a good quality speed converter? the thor ones dont seem to be available anymore.

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