ISperform

Okay so I recently picked up this 08 IS250 it needed a motor. So I swap the motor got it running. Everything working perfectly except for the p0713. So I have ran through a couple things already. I know alot of Lexus owners shy away from tearing there cars apart i'm not one of them. So I've already pulled the tranny pan replaced the harness inside the transmission thinking the sensor might be bad. I've also replace the coolant temp sensor. I read somewhere that that works in conjunction with the transmission temp sensor. Is there something that I missing? Does anyone have any insight or ideas on what get rid of this code? so I can enjoy my IS.

MikeFig82

iTrader: (13)

That's a fuel trim code? Are you sure it's that code? My bad I read that code wrong.

ISperform

Yes its the right code p0713 transmission fluid temp sensor circuit to high. I'll delete the code when cold and it won't come back for about 15 min of driving. It will shift into 5 just fine but never 6th. Then the lights come on and I'll have to delete it Everytime I want 5th.

MikeFig82

iTrader: (13)

Yes I read the code wrong. Since you swapped motors. Did you lose any trans fluid? Searching the code says check fluid levels. Dirty fluid etc... Here's the procedure for diy.

ISperform

No I have since replace the wire harness inside the transmission that has the temperature sensor attached to it. Thinking the old one might be bad. I swap the filter while I was in there and refilled to the proper level. Following lexus's fill procedures.

MikeFig82

iTrader: (13)

Do you think it's a malfunction with the trans PCM?

ISperform

I'm not sure if it's a malfunction with the PCM or the trans it self. So I came on here to see if anyone else has ran into this problem. I don't think it would be the PCM but I did pull it from the bay with the wire harness. I can double check connections at the PCM. It's kind of hard to mess those up though since they push and lock into place.

MikeFig82

iTrader: (13)

Well since we're here trouble shooting. How did you change the ECT? I've checked on how I would do it. I see no room from up top. As it's located at the firewall.

ISperform

Lol I pulled the battery out and unplugged a couple sensors so I can move the wiring harness out of my way. I reached back there and unplugged the sensor then with a long extension and a deep wobbly I was able to get it loose I had the new one ready. When the old one came out the new one went in and I didn't lose that much coolant.

MikeFig82

iTrader: (13)

Yeah I was in that area a few days ago, and couldn't even reach to feel for it. I'm assuming I'd have a better view if I pulled the TB off too.

Well I found this link. Something to look at is problems with the TCC.

https://www.freeasestudyguides.com/a...er-clutch.html

2013FSport

iTrader: (2)

Was just gonna say if it thinks it never comes up to temp, then (and I could be wrong here) it never goes into lock up. Then the fluid temp will shoot high. I think it uses engine temperature vs trans temp but ??

You need techstream or equivalent and see what the temperature is.
Find the specification for the sensors resistance at room temp and say at 195°F. Measuring it after it sits all night should yield ambient temp. If needed you plot a graph and see if it outputs the right value.

Next step would be to use a variable resistor to the input at the trans connector and watch in software to see if displays the right values!

FWIW I want to say there are two temp sensors if memory serves me...


Do a search for "A760E.pdf" and do some reading. There are several pdf's out there. Keep in mind the tundra and tocoma use the same trans.

ISperform

Ya it's a little tough to get at but it's doable. Thanks for the link. Hopefully it's not the TCC. I would think I would get a different code if it was but I could be wrong.

ISperform

That's a good idea also the trans is a A760h I looked it up and the info is minimal. I know there is one TFT sensor inside the transmission where is the other?

2013FSport

iTrader: (2)

Yes... you would.

2013FSport

iTrader: (2)

The guts are the same. Its simply how it connects. E vs H.