Coolant Temp Sender (sensor)

[17LexusOwner]

I tried doing a search on this, but that stupid new google search goes through every forum and it gives too many results :/ sorry if this is a repost.

Anyways.

Now that it's just turning summer I can find out different things about my car than during the winter. One of these rather annoying things is that when my car has warmed up every once in a while (around 2-5 times a day if i'm working) my tranny will miss shifts.

What I mean is that when I'm taking off from a stop or a very low speed (when the car is in 1st) it will start normally and then when it's supposed to shift into 2nd it seems to miss and go into 3rd or 4th (haven't pinpointed which yet) The odd thing is it doesn't make the car stall or bog at all, but if you push the pedal down it just won't give the amount of power to the wheels. It's kinda like if you were riding the clutch on a manual and you had the clutch slipping while flooring it. (possible bad clutch packs?? I sure as hell hope not)

Now I'm almost sure that this is an electrical problem because it also effects my over-drive button. Sometimes when i turn off overdrive it will stay in 4th gear.

The really weird part about it is that when it skips that gear I can push the "turbo" button on my pedal quick and it will kickdown to 2nd like normal and then shift fine. Sometimes though it won't even kick down after pushing the button under the pedal and i'll have to manually put it in 2nd then shift back to drive. :/

My conclusion is that it's caused by a faulty coolant temp sender(sensor). My temp gauge reads lower than normal also.

Any thoughts?

[93ls400walt]

I would check your cel codes. and search forum for trunk hinge wire. The wire frays on the drivers side trunk hinge and can cause all types of problems. Pull the black trim off the hinge and unwrap the wires toward the back seat past the " U " bend in the wire. Look for breaks and cracks.

[SKperformance]

I would check your throttle kick down cable.

[17LexusOwner]

I'll check both those things. Pretty sure throttle kickdown is fine because it kicks down flawlessly when it's not doing this crap.

Also why would that cable be effecting my O/D switch.

[steve2006]

I would check your throttle kick down cable.

I agree.

I repaired my starter motor last weekend and managed to adjust the kickdown cable incorrectly ( over adjusted) this resulted in a heavier "jolt" when going into drive and reverse and gave the same gearchange syptoms you have.

I thought the kickdown cable was just for kickdown but it also tells the transmission the throttle position as well so alters the gearchange timing accordingly.

[93ls400walt]

How did you adjust the cable?

[17LexusOwner]

Just an update guys.

Checked the codes for my tranny. Found out I have faulty electrical in the transmission.

No. 2 Solenoid has an open or short circuit.

OD direct clutch speed sensor signal malfunction.

Has anyone had any experience with those? I called the Lexus dealer to get estimates on the cost of those, but I'm still waiting on a call back. I'm expecting to crap my pants with the price.

[fsuguy]

17lexusowner,

I have had the exact symptoms you have described - when cold the car usually performs well, but when it warms up, it appears to drop into 3rd instead of 2nd. I checked all the trunk wiring but no problems. When I checked the OBD codes it said solenoid #2 and/or the speedsensor #2 are bad! I dropped the pan and tested both the #1 and #2 solenoids, but both have resistance within tolerance, and both open and close(?) I have not changed my sensor #2 as yet, but will do so when I get the time.

I would like to know how you resolve your problem, though.

TIA

fsuguy

[17LexusOwner]

Hey it's great (and sad) to see that someone else has the exact same problem. Let's me know that what I was looking into is what's wrong with it.

Right now I'm looking into buying a used transmission and swapping the solenoid and O/D sensor from the used one. The used trans has 106k on it and it's $300.

Whereas the brand new solenoid and sensor from Lexus would be $400.

I'll do some testing next week in my auto class and then report back.

[SKperformance]

Why not just buy 2 new solenoids instead of a whole tranny.

[AcidFire52]

Why not just buy 2 new solenoids instead of a whole tranny.

Hey it's great (and sad) to see that someone else has the exact same problem. Let's me know that what I was looking into is what's wrong with it.

Right now I'm looking into buying a used transmission and swapping the solenoid and O/D sensor from the used one. The used trans has 106k on it and it's $300.

Whereas the brand new solenoid and sensor from Lexus would be $400.

I'll do some testing next week in my auto class and then report back.

[PureDrifter]

Why not just buy 2 new solenoids instead of a whole tranny.

Hey it's great (and sad) to see that someone else has the exact same problem. Let's me know that what I was looking into is what's wrong with it.

Right now I'm looking into buying a used transmission and swapping the solenoid and O/D sensor from the used one. The used trans has 106k on it and it's $300.

Whereas the brand new solenoid and sensor from Lexus would be $400.

I'll do some testing next week in my auto class and then report back.

labor (if you're not doing the work yourself) to install a trans is a LOT more than labor to install 2 solenoids since you can do that without taking the trans out of the car.

[lexfourcam]

damn guys this is the same *BLEEP* wrong with my car. ive needed solenoids its causing it to struggle and run really *BLEEP*ty. i miss the smooth running and shifting tranny im gonna get my cel checked and see which solenoid is messed up in mine.

[fsuguy]

Hey it's great (and sad) to see that someone else has the exact same problem. Let's me know that what I was looking into is what's wrong with it.

Right now I'm looking into buying a used transmission and swapping the solenoid and O/D sensor from the used one. The used trans has 106k on it and it's $300.

Whereas the brand new solenoid and sensor from Lexus would be $400.

I'll do some testing next week in my auto class and then report back.

17LexusOwner,

You may actually be better off getting new solenoids; everything I've read about this issue seems to indicate that Toyota had a "sticking solenoid valve" problem with these trannys. That's a lot of work to go thru to have the same problem crop up again!

:o

[fsuguy]

Hey it's great (and sad) to see that someone else has the exact same problem. Let's me know that what I was looking into is what's wrong with it.

Right now I'm looking into buying a used transmission and swapping the solenoid and O/D sensor from the used one. The used trans has 106k on it and it's $300.

Whereas the brand new solenoid and sensor from Lexus would be $400.

I'll do some testing next week in my auto class and then report back.

17LexusOwner,

You may actually be better off getting new solenoids; everything I've read about this issue seems to indicate that Toyota had a "sticking solenoid valve" problem with these trannys. That's a lot of work to go thru to have the same problem crop up again! Check into Rostra Precision control systems. They may sell you a 2-solenoid module out of their catalogue for around $80.00; the part cross refereces with the toyota solenoids.

:o