Juiscr

I've had my 2013 is350 for around 7 months now and the car has been relatively reliable. I got it at 93k miles and just last week hit 100k. Within the first three months of ownership the transmission started slipping and threw some codes. If I remember correctly they were pressure control solenoid c and d. The car got stuck in third gear, so I put it in the manual mode and shifted it up. A couple days after I took it to the dealer and did a transmission fluid drain and fill along with a solenoid test. They said the solenoids were fine and couldn't reproduce the problem (how great!). The car ran fine up until recently where occasionally it would get stuck in third gear and id have to manually shift it up. The other day it finally popped a cel, so I took pictures of the codes, cleared them, then drove home. This morning I decided to scan the car one more time and I finally got a permanent code for p2714. I'm thinking about updating the pcm, and replacing that solenoid. I'm in college with payments on the vehicle so replacing the transmission isn't really an option. Can you guys give me any advice?

Zmon

iTrader: (2)

This is a mechanical issue, updating your PCM will not fix it. This is def one of those issues that will take some time to diagnose and money to fix as the solenoids aren't exactly cheap. Future note, a used trans is about $800-1000 for our cars. I'd give this thread a read: https://www.clublexus.com/forums/is-...earch-diy.html

Oro

Before you start throwing parts at it, I suggest cleaning it up.

Put in some B-12 or SeaFoam, drive a few days. Do a drain/fill and add some Lubegard Red (or better yet, Lubegard or Redline ATF with an ester base). This will clean up the valve body and refresh the seals on the solenoid pistons, clean the piston bores.

I’ve revived a few Aisin transmissions this way, and one Honda. No guarantee, but the low cost and ease of this before surgery makes it worth trying.

2013FSport

iTrader: (2)

I would not recommend any ester based products intending to stop leaks or restore health. Yes, they can create a temporary fix by swelling rubber that resides under many Teflon slip rings but when the little blue pill wears off and the swelling resides the internal leaks will continue.

A factor that many miss is this. Solenoids are slaves. They are given a command and hopefully they execute it. They do not transmit data about there well being or if they followed the command. The ECM/TCM does watch them for opens and shorts but those give different error codes. All of that said, the only way the ECM / TCM knows they did their job is by monitoring the turbine input shaft speed and comparing it to the output shaft speed. Then it uses a lookup table or map to establish it was in 2nd gear and is now in 3rd gear (example) as it knows each gear ratio and the amount of acceptable slip (not to be confused with torque converter slip).

So, to understand the problem one needs to verify the solenoid is/is not working. Does it change state, and does it flow fluid? If it does, its likely not the problem. The problem here is the pressure control solenoid isn't just an off/on solenoid its more like a fuel injector using pulses to to regulate pressure. You best bet here is to connect a gauge to the transmission and read the actual line pressure.

Bottom line, don't assume a solenoid error means the solenoid failed as its just a pawn that was given a command. If I have time there is youtube video out there of guy build an A760 and during the assembly he uses shop air to pressure test clutch packs in the drums for all forward and reverse gears. This is done with the valve body off and its lets you know if they engage properly or if they are simply a big internal leak...

PS i used to build transmissions. Read the thread Zmon pointed too and look up valve body repair services as well as updates to the A760. This transmission goes in V8 Tundras, Sequoias, and other vehicles so a reconditioned valve body could be a good start as it would be fully tested and have updates applied.

Oro

That is not how ester works on synthetic rubber - you are thinking of different aromatic hc’s.

Esters are effective at conditioning, not ‘swelling’ seals. That’s why they are spec’d in very demanding applications like helicopter gear boxes, etc., where seal failure is critical. It’s a common misunderstanding of the different chemistries. This is one of the reasons the highest end oils use esters as components.

Redline oil is usually pure ester base, among others. They also offer outstanding cleaning ability because of their polar structure.

2013FSport

iTrader: (2)

You are correct. There was some snake oil stuff back in the day often times made a bad situation worse. This erra had fluids that allowed oil flow areas to varnish and cleaners would in fact remove said varnish and create both internal and external oil leaks and rubber seals would swell like they were dipped in brake fluid. For some reason ester stood out, but I should have read about it before writing that.

Inactive

I had this issue a while back, the car just wouldn't shift into 5th and 6th, and I also had check VSC and the traction control light on. Took out a scanner and I also pulled code P2714, did some research and solenoid S4 was the problem. I ended up buying a new aftermarket S4 solenoid, draining the old transmission fluid, installing the new solenoid, and then adding some new transmission fluid. It's been over 6 months and it runs smoothly with no issues. Do you also have a Check VSC indicator? What about shifting into drive? Does that cause the vehicle to jerk?