Transmission not shifting properly and code p1725

Hello, I'm Danny.

I've attached picture diagnostic steps below relating to the trouble code P1725 you provided.Hope this helps and thanks for using 2CarPros.

Thanks, I would get back to you.

You're welcome!

Yes, keep us updated and let us know if you have any further questions about this issue.Hope this helps and thanks again for using 2CarPros.

Danny-

Hi, thanks. I removed the NT speed sensors and tested it's resistance it read 667 and 686 respectively, the voltages was extremely low. Is this a good sign? So I just cleaned it.

It sounds like the input shaft speed sensor is bad. here is how you can replace it. Check out the diagrams (below). Please let us know what you find. We are interested to see what it is.

Hello again.

Yes, the resistance is within range.. It seems you are having an issue with the ECM then. You can find them remanufactured online but I suggest to buy new. I can give you a part number but I would need your VIN - vehicle identification number to confirm proper part. Hope this helps and thanks again for using 2CarPros.

Danny-

Hi, thanks Danny. I changed the NT sensor and all is well. I guess it was damaged a little. Thank you once again.

You're welcome!
Glad you were able to resolve the issue. Hope you will use or site again in the future.

Danny-

Sure, definitely.

I had my alternator replaced now my truck is at 4rpm when I do 60mph, anyone can help me, is it possible that the alternator has anything too do with this, and why is the rpm at 4, feels like the trannie will not change gears feels like it's stuck in 3rd. trannie is not oringianall had it replaced severall years ago. Has around 30k miles on it. Machanic claims I need a new computer now. Trust him just not a very good mechanic

if he is not very good then why are you there as he may have made a mistake in the repair???

have him go over all his work to see if he left any connectors off before assuming you have an internal issue

Roy

How do you know if anything is bad unless they make a mistake 2 x or more in my case that's what happened,
But the problem is still the same, not why I use the mechanic but why after he replaced the alternator my rpm are at 4 while doing 60mph. please just looking for help

I'm reading there's a possibility that the alternator can be the issue, can anyone please help me with this as I'm at a loss and wanna resolve the issue,, can anyone please help me

I brang the truck back too him and of cause he hooked up the computer and tells me now that it's the computer on the truck, I have too beleive that's not the issue, The car ran beutiful before the replaced alternator, The car is a 2001 lexus and has more sensor's then egine parts, I read that an alternator can mess with multiable parts, my suspsion is he put a cheap alternator and will not admit he messed up, Who likes too admit fault

if the new alt is bad and putting out ac voltage instead of dc voltage, then yes, it could cuse other issues but not shifting into overdrive would be 1 of many other issues.

did he say there were any codes when he put it back on the scanner??

Roy

ASEMaster6371
You seem too have a great reputaion, I would and need your expertise, via phone or e-mail. I'm willing too pay but I really need someone who knows what there talking about. Can you help.As too there a severall issues I need too have answer too

let me know how I can help you.

Roy

ASEMaster6371
I'm sorry I'm new too using this siteand not geting the hang of it, Yes he gave me a code of some sort but when I looked it up it said it meant that the car was being tested, keep in mind that the check eng light is on so its not giving me an ans, the check eng light is a whole other matter that I'm dealing with. But the light was on before That's when i relized he was not a good machanic, we where still dealing with that issue and being my sister uses the car she had him change the alternator, It seems the more he touches it the more i see he just guesses at the problems
All this, like I said He seems honest and was very fare in price, He worked on my Ford explorer and never had a problem with his work, I just beleive that the 2001 lexus is way out of his league

I was driving my car and the gears started slipping and then it would go passed 2nd gear and I had to drive in 1st gear as far as I could and then the car wouldn’t drive anymore. Now I can shift out of park and then it goes straight to neutral and doesn’t drive. I have had my transmission cooler replaced recently and when they did my gear shaft code was showing up. I checked the gear shaft from the inside of my car and it is intact and perfectly fine. I need help.

I don't have the code in front of me, as far as the eng light He changed the oxygen sensor, then I find out it has 3 so I brang the truck too someone else and they said it was bank 1 sensor he changed that and still the light is on, I put a new gas cap cleaned the MAF sensor and checked for cracked of leaky hoses myself, still light is on, I'm guessing It might be bank 2 sensor but mean while, Now I have too deal with this RPM before I resolve the egn light as I beleive the high RPM can kill the eng of the trasmission

Good afternoon,

What is the code number that came up?

Did you check the fluid level?

How long since you changed the oil, filter in the transmission?

https://www.2carpros.com/articles/how-to-service-an-automatic-transmission

The fact that will not move means either the level is too low, the filter is clogged or there is internal failure in the transmission.

https://www.2carpros.com/articles/automatic-transmission-problems

Roy

ASEMaster6371
Ive got the code , When we took it for a test ride he had the testing computer hook up while driving and the only code that came up was CODE 1201 He ask me too write it down and needed too look into it
any help , Thank you again

Reconfirm the code. P1201 is not listed in our database nor in generic OBD-II code list.

Yes sir that is the code it read, That's what I mean the Lexus is way out of his league and now I pay for it,. I'm going today too get a reading from another mechanic as soon as i get the new reading I will post it, Any how have you ever heard of a problem like mine refering too the RPM @4 while doing 69MPH, after a alternator change

Symptom indicates the OD is most likely not engaging. Does manually turning the OD OFF and ON switch makes any difference to the engine rpm?

If P1201 is the confirmed code, that would mean a fault with the PCM as any code not listed means the PCM is faulty.
Electrical problems can be affected by disconnecting the battery, low or excessive charging. Power surge can damage PCM too.

No, I've tried playing with the O/D button as i drive and nothing, at first playing with it and bringing the car too a stop would help ,I drove about 10 miles with the O/D on and when I took it off the car was fine at 2 RPM at 60mph but now I jsut can't get it down, Should I try fuses ??? what would I do too see if the O/D is at fault

I would suggest getting another scan done to check for trouble codes.

When the O/d switch fails to work, it could mean the transmission valve body has a fault.

Apart from checking fuses, I would suggest checking the ground circuits. If any is poor, especially for the transmission and its control, it can cause erratic shifting patterns.

Do you think that the alternator has anything too do with it, I find it strange that after he put's an alternator in I start having RPM problems

I got a read out from Auto Zone, and there telling be it's the NOC sensor , can that be the culprat for the high RPM @ 60 MPH

And as for as the EGN light after having OXY sencor and Bank 1 sensor changed they tell my the read out says bank 2 sensor

Can this be the answ for the RPM's at 4 doing 60mph and for EGN light ,, can it be that simple ?????

Thank you for all your advise and help greatlly appreciated

In the morning, when starting first, the transmission seem to shift through all gears. After ten minutes of driving, it shifts through 1st two gears but, does not shift to higher gears. In the evening, after parking in the sun for 8 hours, the transmission does not shift beyond 2nd gear at all.

I checked the fluid level and color and odor. They seem to be fine.

TY for the donation

Get the coolant temperature, throttle position and vehicle speed sensors tested thoroughly if they all okay -could be coming from the internals of the transmision-which probably needs to be pressure tested to identify the problems.

The computer uses this input signals from this sensors to command and control the upshift/downshift/overdrive/lock-up thru shifting solenoids.

code for lexus 2001 300RX
PO330
PO171
PO174
PO325
Can anyone explane these codes, and also why it says MAF concern, does that mean I should change the MAF sensor as well?
RPM,s at4 while doing 60MPH NOC sensor sound write

Ans ENG light on, sensor 2 Bank 2 sound write

Thank You

P0171 and P0174 are system running lean conditions. It could be vacuum leaks or a host of sourves and does not indicate what component is faulty. It could also be due to low fuel fuel pressure or caused by the knock sensor.

P0320 and P0325 - Knock sensors fault, left and right bank respectively.
Knock sensors failure are common for such vehicles.

All the 4 codes have no relations to the transmission not shifting to O/D which can be due to a fault with the O/D solenoid stiicking.

Sometimes problems are coincidental and you should not keep thinking it is related to the alternator replacement. Test the O/D solenoid first.

Just I understand
When I hit 60 mph and the RPM are @ 4
Feelin as the car not shifting into the next gear that's call overdrive ???
I feel the car shift 1st 2nd and 3rd
The next is call O/D ???

KHLow2008
I also wanna thank you for explaining in detail too me
That's a Hugh help
Thank you

Yes, OD is 4th gear and can be manually turned off with the switch on gear shift if it is working correctly.

Let's say I get the car up too 50-60 MPH if I hit the O/D button ( manuall O/D BUTTON ) I would see and notice a differance in the RPM's as I;m driving ?????

And if yes, and I do not see a RPM differance, Then 1st thing is check the cilynoid Would there be a fuse that might have blown for O/D button ????
and how do I check cilynoid

Yes, that is the situation it should be.

When you hit the button and if the O/D OFF light comes on (ensure the light comes on) , the rpm should increase as the gear downshifts. If there are no changes, that means the transmission is in 3rd speed which runs at a higher rpm.

If you have a scan tool, that would be easy to test the solenoids. Usually when a solenoid fails, the transmission would go into limp mode and the MIL would indicate. You were not able to retrieve any trouble codes for transmission failure so there is a possibility the problem is with the transmission manual controls such as shift valves or clutches.

KHLow2008

Just wanna let you know I really appreciate you taking the time too advise me,
You put me on the correct track, The only thing is that maybe I was not explaining my problem correct
as far as the NOC snsor and transmission, I've been told by severall mechanics that when ( NOC ) they go the transmission will go in limp mode affecting the O/D in order too protect the bad readings
I went too Lexus today and they said the same thing that if the NOC sensor go It would be a strong possibility that the car would not shift too O/D at 60MPH..
But so far your the only one who help me and put me in the right direction and explained the code readings too me
What is your opinion on the NOC putting the trannie in limp mode too protect car , is that a possibility at all ????
Keep in mind I value your opinion above all others so far

I could find not any relations to the knock sensor and engine going into limp mode. So far all the vehicles I have repaired regarding knock sensor problems have never had any complaints of the O/D not working nor of vehicle going into limp mode.

What the engine control system does is to retard the ignition timing and that would affect engine performance.

Whether the explanation given is true or not, let us put it aside first. Since the knock sensors are bad, have them rectified first and check the engine coolant level. Overheating is the most common cause of knck sensor failure.

Once the knock problems are resolved, we would know if the O/D not working is linked to it.

Before attempting repairs, clear the codes and go for a test drive first to check if the codes comes back. Try to drive with gradual acceleration to avoid pinging so that you can test the transmisison first.