Rmatthews

I have a Lexus is250. Code scanner says shift solenoid C. If I start off and let the car shift to 4th gear before it passes 21mph then it will shift all the way to 6th gear and drive fine. If I accelerate any faster, it will stick in 3rd gear and never pass that point. Anybody had this issue ? I’ve read that it might not actually be the solenoid but I have no idea. I’m hoping to narrow down what part of the transmission might be going bad before I have to replace the whole thing.

AMIRZA786

How many miles on your IS? What year is it? You may want to start with a transmission fluid change. It has to be done properly if you do it yourself, or even if you have a mechanic do it. In a lot of cases this resolves the issues with shifting

Rmatthews

It is 2006, Lexus IS 250. I honestly don’t know how to change it myself with it being a sealed transmission but I can check into it with a shop. Thanks.

AMIRZA786

Make sure the shop you take it to knows the proper procedure. You can search it up on this forum, @2013FSport has documented it on his maintenance thread. A few months back I swapped out the AT fluid on my 2010 IS350, and it's been buttery smooth ever since

jizz4jazz

iTrader: (1)

Common problem with people not changing the transmission fluid early enough. How many miles in on your car?

Rmatthews

175,000. I’ve read that some people have had success with changing it in this type of transmission but I’ve also read many that never had to.

jizz4jazz

iTrader: (1)

I would still try to replace the damaged solenoid and drain/ refill + change transmission gasket + filter. I had mine done at 140k and its at 160k, shifts like new.

AMIRZA786

Swapping out the ATF is a good starting point, as these Toyota/Lexus transmissions are pretty durable as long as they are maintained. I have a 2006 Camry SE with 155K and a 2013 Sienna with 144K, all lived hard lives and the transmissions are still strong. You may need to swap the fluid out more than once, on my 2010 IS350 the first time I swapped the atf I had some issues with shifting and sudden jolting, my mechanic swapped the fluid a second time and now everything is smooth

Rmatthews

Thank you both, I will definitely try this and let you know what happens!

2013FSport

iTrader: (2)

Spidy sense said to read trans thread... and lookie, a mention.


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Here is a link. If you have a means to get it in the air safely and level, it doesn't take much for tools.

#2is-transmission-fluid-change-diy-a760e-rwd

Using the method outlined above and 3 gallons of fluid, I easily got more than half of the fluid out in one service.