Code 42 Fix

[peter richards]

just a thought if it is getting code 42 errors , and as you said could get something else .

getting complicated now ill just leave it , dont use the active spoiler , and will very rarely get it up over 80 , so i think ill live with the lights

[Blackie]

But why do you want to reset the ECU in the first place?

 

I dont, He asked how to and i told him

[Guest jorisLEX]

hi everyone.

 

i'm new around here and this topic sounds femiliar to me.

 

when i bougth the supra it was running in MPH, so i put the speed convertor away and back to KMH.

 

so when i was driving, MIL and red lashing light. error code 42 speed sensor.

so now i read this topic i did the code42fix, pink wire from loom side , join with the bleu/red one.

 

perfect, no error code, everything good; i thought ?? now my car is back limitid to 180KMH.

what did i wrong, or is my speed limiter broken or somthing??

 

kinds regards

from belgium.

[Jellybean]

I am a little confused

 

• On the TRL Schematic it illustrates you join the Loom pink side to a blue wire
  
• On the Diagram off her it illustrates you join the Loom pink side to a red/blue wire
  

Whats correct?

 

TRD Schematic

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

 

Diagram off here attached

[bondango]

T7-5 is input to ODO from the Speed Sensor

T7-6 is out put from ODO buffer to PPS/ECU/AS

 

The Lower diagram is the Code 42 fix if there is a problem with the ODO buffer, i.e. you just send the speed signal direct to PPS/ECU/AS instead of the Buffered Signal

 

TRL diagram is there to show you were the !:! and the 5:8 converted Speed sensor signals go

 

1:1 (un touched Signal) goes to PPS/ECU/AS

3:8 (converted speed signal) goes to Speedometer and ODO (odo buffer output is not used)

[Jellybean]

Becasue I got Code 42 error thrown

 

First steps to trouble shoot is to by-pass the ODO buffer? Since we are in KM down here I am correct in joining the Loom pink side to a red/blue wire.

 

after ECU reset if , Code 42 is still thrown ; Speedo (loom & unit), short circuit or the actual sensor are the next items to truoble shoot

 

This reeally is turning into a pitta of a diagnostics; I am going to open up an SSI branch down south ha ha

[bondango]

Yep Snip T7-6 and join its ECU side to T7-5

[stevie_b]

Yep Snip T7-6 and join its ECU side to T7-5

 

Just my 2p worth but if it were me, based on what I've read on your other thread I wouldn't do that just yet.

 

You said your speedo works intermittently: this suggests the problem is somewhere between (and including) the speed sensor itself and the speedo cluster. The speed sensor signal goes from the sensor, then into the speedo cluster, then spat out from the speedo cluster into the odometer, then spat out from the odometer (possibly via PAS and active spoiler circuits) into the ECU, in that order. So, tinkering with the odo won't work if the speedo occasionaly drops out.

[Jellybean]

Yep Snip T7-6 and join its ECU side to T7-5

 

Very technical; the wire colors would of done me ha ha

 

Thanks Marty, I will double check my wiring because I have this done hmmm onto the next step , Speedo Loom

[Jellybean]

Just my 2p worth but if it were me, based on what I've read on your other thread I wouldn't do that just yet.

 

You said your speedo works intermittently: this suggests the problem is somewhere between (and including) the speed sensor itself and the speedo cluster. The speed sensor signal goes from the sensor, then into the speedo cluster, then spat out from the speedo cluster into the odometer, then spat out from the odometer (possibly via PAS and active spoiler circuits) into the ECU, in that order. So, tinkering with the odo won't work if the speedo occasionaly drops out.

 

When my speedo comes back online, what confuses me is the boost controller not also coming back online too in tandem with the speedo (Boost controller has a speed KM/H display)

 

Based on the TRL didagram pin 13 on the Speedo Loom was a little slack (think it is Green /red) not too sure what this is for but I did tighten it up

Edited May 20, 2011 by Jellybean (see edit history)

[stevie_b]

When my speedo comes back online, what confuses me is the boost controller not also coming back online too in tandem with the speedo (Boost controller has a speed KM/H display)

I've got no experience of boost controllers but those symptoms don't surprise me. Unless the boost controller has its own dedicated speed sensor (unlikely I would think), it'll be tapping into whatever speed signal is passed around the stock loom. If that signal is being choked off somewhere near the source, then it's not surprising that the boost controller's speed readout is also intermittent at the same time as the stock speedo.

[Jellybean]

I've got no experience of boost controllers but those symptoms don't surprise me. Unless the boost controller has its own dedicated speed sensor (unlikely I would think), it'll be tapping into whatever speed signal is passed around the stock loom. If that signal is being choked off somewhere near the source, then it's not surprising that the boost controller's speed readout is also intermittent at the same time as the stock speedo.

 

The boost controller source is off the ECU, there is a break in the speed sensor loop between the speed sensor and the Speedo. No signal is getting to the ECU

[bobapple]

I had this problem used to get warning triangle and engine warning light pop up at certain speeds and load. Thor rewired my odo not sure how , but no more code 42. This will then allow you to find out if you have any more fault codes I had a rear wheel sensor out which didn't show until 42 was cleared though the ABS light did come on intermittently. Though up to now no one can work out why my slip cont off light is flashing, though not too bothered as it just means the crappy traction control system isnot working.

Edited May 22, 2011 by bobapple (see edit history)

[stevie_b]

I had this problem used to get warning triangle and engine warning light pop up at certain speeds and load. Thor rewired my odo not sure how , but no more code 42. This will then allow you to find out if you have any more fault codes I had a rear wheel sensor out which didn't show until 42 was cleared though the ABS light did come on intermittently. Though up to now no one can work out why my slip cont off light is flashing, though not too bothered as it just means the crappy traction control system isnot working.

This won't help jellybean because his fault is up-stream of the odo. His is an unusual case, not the usual code 42 cause.

FYI, Thor will have bypassed the odo's output buffer circuit.

 

Jellybean: I think you have 3 choices:

1) Substitute your speed sensor for a known working one and see if the problem goes away

2) Substitute your speedo cluster for a known working one and see if the problem goes away

3) Try running a new wire from the speed sensor to the speedo input. This will only work if there aren't any electronics in the stock system between the sensor and speedo, which I can't be sure of.

[Jellybean]

Thank Steve;it only started after I disturbed the dials to fit LEDs ;I will triple check the loom then run through your steps if that doesn't work.just too much of a coincidence for the speed sensor to go after I disturbed the dials. Has to be the loom

[Guest 2jz_mkiv]

This thread just wont die will it? Thanks for everyone's help, I have another curve ball 42 to throw at everyone. I have a 93 auto NA. Ive read the entire thread and understand that the signal goes in this order 1.Speed Sensor 2.Speedo cluster 3.odo 4.ecu

- My Speedometer works properly. No hiccups ever.

- My odometer works intermittently. Most of the time it does not register mileage.

-My O/d off light flashes sometimes, and my transmission acts as if it does not know how fast I am going, and accordingly, it throws in to the wrong gear. Usually dropping in to third at 45-55 mph or OD at 25-35 mph.

-My Cruise control also works when it wants to. It gets power and will turn on displaying "CRUISE" on the cluster, but usually does not set, when it does it fails within minutes.

 

I was going to try the bypass soldering pink wire from loom to blue/red, and taping off the pink from the multiplug. But before I go to splicing I figured it might not work because my odometer is not working properly. Any advice is greatly appreciated.

Edited July 15, 2011 by 2jz_mkiv
made easier to read (see edit history)

[Guest 2jz_mkiv]

got impatient, I did the bypass and here are the results:

I skinned the blue/red and spliced in the pink wire from the bundle of wires. I then blanked off the pink out of the multi-plug. Just as stevie indicated (I was going to swap out pinks like Dave instructed if this didnt work)

My speedometer still works and was unaffected

My odometer is still working intermittently, it seems to have been unaffected (still problematic)

*The O/D off is no longer flashing and my transmission is getting a solid signal, no more shifting erratically to inappropriate gears!

*My cruise control is now working solid as well!

I can live without an odometer/trip computer for now. Clearly the problem is there. Thanks for the help guys I hope this helps someone in the future.

[Suprakeith]

Well i have code and am going to try the same fix as above tomorrow just hope it goes well and gets rid of engine light