[pjames]

Hi there,

This reads like a lot of other posts I've read in the last few weeks trying to troubleshoot this. My parents have owned this car since it was a demonstrator, always services with the dealer they bought it from (i know). They got a check engine light in outback australia, along with lazy shifting/over reving issues-  and got the lovely $14500k quote from hyundai to fix .

We towed the car back to Sydney (thanks nrma!) and after a bit of research on valve body repairs and other problems, decided to go for a second hand (warrantied) transmission. This was installed by a mechanic (not Hyundai)  but code p0700 came back almost straight away (~10mins of driving). I can clear the code and get some normal driving out of it for a short period of time. I can also manually put the car in 2nd and drive without codes or issues. So I am turning to forums for advice in terms of next steps/troubleshooting

Possibilities are from searching here;
Second auto was faulty (I have warranty, but very little appetite to spend another $1k to replace, or DIY the transmission)
Dry solder inside valve body (probably could DIY)
Replace valve body (probably could DIY)
Sell as is/crush the car
TCM/TCU I've seen referenced

Any other troubleshooting steps I should consider before shelling out for a new valve body that may/may not fix the problem or just moving the car on? T
Peter

[tw2005]

Hi there,

This reads like a lot of other posts I've read in the last few weeks trying to troubleshoot this. My parents have owned this car since it was a demonstrator, always services with the dealer they bought it from (i know). They got a check engine light in outback australia, along with lazy shifting/over reving issues-  and got the lovely $14500k quote from hyundai to fix .

We towed the car back to Sydney (thanks nrma!) and after a bit of research on valve body repairs and other problems, decided to go for a second hand (warrantied) transmission. This was installed by a mechanic (not Hyundai)  but code p0700 came back almost straight away (~10mins of driving). I can clear the code and get some normal driving out of it for a short period of time. I can also manually put the car in 2nd and drive without codes or issues. So I am turning to forums for advice in terms of next steps/troubleshooting

Possibilities are from searching here;
Second auto was faulty (I have warranty, but very little appetite to spend another $1k to replace, or DIY the transmission)
Dry solder inside valve body (probably could DIY)
Replace valve body (probably could DIY)
Sell as is/crush the car
TCM/TCU I've seen referenced

Any other troubleshooting steps I should consider before shelling out for a new valve body that may/may not fix the problem or just moving the car on? T
Peter

You kept the old box did'nt you?

[tw2005]

What other codes have you recorded? P0700 is the TCU telling the ECU there's a transmission fault but there should be another code associated in the TCU that causes that request to the ECU.

[tw2005]

Has all the wiring been reconnected? there's the inhibitor switch harness, speed sensor located at the front lower rh corner above the pan and another at the rear of the box

[nzenigma]

@pjames

Im not big on coincidence. Gut feeling is that your transmissions are both ok.

I would check connections that tw has mentioned, check for corrosion or a broken wire.

Then go and find another TCU