Whats up guys I'm new to the forums so sorry if I do anything incorrect.
I have a 2007 Lexus IS350 with roughly 135k miles on it only modifications are RR intake and HKS hi power cutback. The other week when I was doing my transmission service I accidentally overtightened the bolt on the filter and cracked my valve body. Once I put everything together (with cracked valve body) it wouldn't go reverse so of course it had to be replaced. I gave the car to one of my dads close buddy that runs a transmission shop and he replaced the valve body changed the filter and put in new fluid car shifts all 6 gears and goes into reverse, only issue is that when I accelerate a bit rough off a dead stop the car in first gear will redline for a split second and then shift to second gear, I also noticed that it shifts a bit harsh on first gear to second when driving slow compared to how it shifts from 2nd to 3rd and so on. I've tried to do some digging but couldn't find anything of why it does this. Some people I spoke to said its because the ECU has to relearn the new valve body but I don't think that's the case. Since then I've probably only driven the car about 300ish miles but no speeding or harsh driving at all. If anyone has any idea of what this can be please let me know!! Thanks and sorry for the long post lol

 

About 2 months ago I had my Transmission fluid flushed for my 2010 IS350, and like you I began to experience issues such as sudden lurching, holding gears and sudden jolting gear changes. I took it back to my mechanic and he did a second flush, as well as reset the ECM memory (ECM relearn) and everything has been fine since. It's either 1) fluid is too low, 2) To much fluid or some debris from the old leftover transmission fluid is messing things up. Also an ECM Memory Relearn may also be needed (according to Lexus its required).

If the fluid change is not done right and according to the steps laid out by Lexus, the problems you are having can occur, or you could damage the transmission

https://www.clublexus.com/forums/is-...ght-turns.html

 

hmm interesting, so after driving it for a few hundred miles (about 150 miles since posted this) the 1st gear redline isn’t an issue anymore but I feel like when I’m driving around 10-15mph on 1st gear and shifts into 2nd it feels a bit harsh not very harsh to the point where the car jumps but I can tell it shifted. Maybe I should go to the dealership and see if they can reprogram or my Ecu/ tranny? Compared to when I first got the car back after the service it definitely feels better either that or I’m just being paranoid lol. Do you by any chance know how much the dealer would charge for a reprogram?

 

I would assume the dealership would do it as it's a step listed in their manual. I would take it back to them, it may be that the fluid level is lower than it should be. They shouldn't charge you if things aren't working as expected

 

Actually I did the transmission service at a private shop not the dealership so I think they would charge for the reprogram. How can I check the fluid on the car? No dipstick if I’m not mistaken, do I have to remove all the fluid and replace ?

 

No dipstick. Go to the link I posted earlier, it will give you more info on this. It's not for the faint of heart, that's all I can really tell you

 

Snapshot is this:
Grab an OBDII wireless adapter and buy the phone App OBD Fusion as well as the Toyota Lexus PID pack. $45 total.
Put it on stands so it is level and leave it over night..

Read this... #2IS Fluid Change
https://www.clublexus.com/forums/is-...a760e-rwd.html

 

I have a 2007 Lexus is350 RWD 143k miles and got this following code 2 times now (p0894) Both times I reset the code and does not appear until 4-5k miles. Aside from that the car drives good but I do sometimes hear a clunk sound when going from 4th to second gear. Do I need to replace my trans? I believe this isn’t a major issue since it doesn’t come on until I drive a huge amount of miles. Do I need a reflash? Fluid replacement? Taking it to Lexus Monday and will keep you guys updated.

 

I would start with a full ATF flush/purge at the Lexus or Toyota or whoever else have that special machine.

 

Yes, do a full trans fluid flush. While draining the old fluid, give the fluid a smell/feel test. If burnt and/or gritty, you're on borrowed time. The internal damage is done and there's no fixing it with fresh fluid. Hopefully it will give you some more useful life though.

 

Update boys, replaced a few solenoids and valve body with OEM parts cost a lot ok and guess what bull**** waste of money time and huge headache, ended up just replacing the transmission with a used unit 35k miles $2100 and the best decision of my lexus life. If you are having similar problems or any transmission problems just replace the fricken thing and call it. 2 year warranty too btw 🤗

 

Unless the problem is simple, meaning it can be diagnosed and fixed very quickly at little expense, I would the do the same thing you did and just replace it. Never want to play around with a complicated transmission, especially if it's high mileage, and time is money. Glad you were able to resolve the issue

 

Late update but I ended up just replacing the unit with a used one 30k miles and best decision of my lexus life, lesson of the day is if your transmission acts up don’t spend 4+ grand on trying to repair it just replace the unit. Cost me a grand total of 2.1k and runs amazing. Also my throttle body was the main reason why my valve body got jacked up, go figure.

 

What people need to know is this; unless the codes reported say things like Open or short at valve X that state an actual electrical failure, replacing valves is often times not the answer.

The TCU tells various solenoids to switch. When the solenoid valves switch the ECU looks to turbine input shaft speed and tailshaft output speed to change.

When it doesn't detect change at the input/output shaft speed it throws a code pointing to the last solenoid that commanded change. This doesn't mean the solenoid is at fault. Yes, it could be, ans that is why it's essential to test the solenoid and prove or disprove it works. If it does work, something else went wrong and it's time to roll up your sleeves and figure it out.

An automatic transmission has a lot going on, so there is a lot to be tested. If high mileage and past due for fluid change, replacement is likely the best option.

 

I just posted this in another thread...

Looks to sorta fit right here too. Likely a good call just swapping it if it never had the fluid changed at >148k Miles.

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