I have a gs300 and about two weeks ago my car started giving me trouble. When I put the car in drive the rpms go up to about 4k and the car starts gonig very slowly all of a sudden there is a hard shift into what seems like 2nd or 3rd and the rpms drop and slowly build up. after a few days the CEL finally came on and read P0750 shift solenoid A.

all sounds familiar right. Ive searched and found some threads on here that brought more questions to me.

first, I do not know how to Identify which solenoid A is. Lexus dosent go by that either. By searching on the site I found that you can check the ohms on the solenoid to figure out which is bad. They should be around 11-14 ohms. I checked mine and they all were at about 6.7 which would mean they are all bad right? would all of them go bad at the same time??? wouldnt I have issues in other gears to if that was the case. The only problem I have is when I am starting out in drive. I do not have issues after that. I am really starting to hate this car, and everytime I start to want to customize the car stuff like this happens. I am ready to just get rid of it. Any help might change my mind.

my tranny pan is off and I would like to fix this ASAP. any help would be great!!! Like I said before I did search there were a lot of threads that didnt have much responce and they were some that helped but not enough.

the ones that did help:
https://www.clublexus.com/forums/gs-...oid-fixed.html
https://www.clublexus.com/forums/per...763-p0715.html
https://www.clublexus.com/forums/gs-...need-help.html

 

no one knows?

 

Free Bumb. Subscribing to see what the suggestions are.

I have had this problem twice. Put the car in drive, and it wouldn't drive for anything. Park, turn it off, start up again, put in drive all good. Weird, and happened only twice in the life of the car. I might be on the same road as you. Your car was probably abused to all hell if you are having a lot of problems. I abuse my car daily though, so not sure if 430s have a beefier transmission.

 

Just a though, have you though about checking the junk yards to see if you can pick up a used trans off another car. Might be cheaper than going through all that work and replacing the solenoids.

 

Yeah man I do drive the **** out of my car but still.... These cars are supposed to be bullet proof.

I dont know im just over it....

I dont know what other car I can get the tranny from but I dont think it will be cheaper and what if that is not the problem. What if its the harness or ecu??? know what I mean. oh well.... I dont know what I am going to do.

 

why don't you try a tranny shop and have the diagnose it. I've seen these trannys go for $300 - $500. I mean there would be labor in it too, but you might as well have someone check it out locally. I would look for tranny deals though.

 

Yeah I think I have found some trannys.

I was also wondering can anyone tell me how many solenoids there are total????? I thought there was 5 but it looks like there might be two more on the pass. side of the tranny pan. There are two more things there with a harness connected to them.

 

ok so here is my question. I checked all my solenoids and they all clicked which means they are good. However I noticed to other solenoids and do not know if these are shift solenoids. Does anyone know what they are.

here are some pics, sorry they are bad. Had to use my cell because I didnt have my camera on me.

shift solenoids right?


then what are these?

 

Wow I wish I could help. I will ask a friend of mine to take a look at this post. He has rebuilt a bunch of trannies. Not promissing anything, but maybe something. No one else seems to be helping.

 

PM Jeff Tsai and see if he can help you. He knows the ins and outs of this car.

 

thanks. Tried Pming him but havent gotten an answer yet. Looks like Im just going to take the car in...

 

Have you done a cross section search or 'blow up' on the tranny? there has to be one somewhere on the internet... (my comment is in regards to figuring what those solenoids are for)

 

I've read a bunch of threads on this topic, but none have given a detailed write up, as the OP has already stated.

So I just dropped my pan to do some maintenance and started doing research and I have figured out most of it, but I'm going to SEMA on Wednesday (11/2/11) so anyone who PMs or replies to this thread, I won't be replying until I return.

For now I'll answer the OP Q's.

Yes Far right is Solenoid A, next to it is Solenoid C. The other 3 solenoids to the left of Solenoid C are NOT shift solenoids so they should not trigger the usual codes.

Right side is Solenoid B and to the left is Solenoid D. All shift solenoids have only one wire running to the connectors. The other solenoids have 2 wires.

When I get back home next week, I'll continue doing some homework and I'll probably write up my own comprehensive thread describing each solenoid, the type of symptoms you will see and some helpful debug tips.

Stay Tuned

 

Many people with GS300 has this Solenoid problems. I don't see many GS4 owners have this problem even though we all share the same tranny.

 

I know myself and another local member both have seen Solenoid problems with our GS4s long long ago.

Basically the same tranny, so in any case the fix will be the same.