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Transmissions Problems... Or The Chip?


jjmancini

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Hey everyone!

I was curious if I could get some help.

My Car:

1990 Lexus LS400

225,000 miles

My transmission (I believe) is being very jumpy. When I accelerate... the tach will go up just fine in first gear, but as soon as it shifts, the tach stops at 2.2 RPM's. And no matter how hard I press the gas pedal or even if I punch it, it will not move, I have to take my foot off the gas pedal, then wait a couple seconds before it can accelerate again.

This happends about 3 out of every 5 times the car goes through second gear. Anyu ideas? Tranmission? Brain? Chip?

Thanks in advance!

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Ahhhhhh..... good thought!

Thanks SK.

Well I took it to the shop and had them drop the pan and clean it out really good and put back in 5 quarts of fluid. So we will see what heppends. Thanks for the thoughts. If there are any other thoughts please let me know.

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You're sure they used toyota approved transmission fluid right? That's one thing you don't want to mess with on these cars, is shelf brand tranny fluids.

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Yeah... I'm pretty sure they are. Becuase they called me up and said "You know, they require a certain type of Tranny fluid. We had to get it from out other store." It was $9.99 a quart.

Crazy. So I think they did. Thanks!

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Yeah... I'm pretty sure they are. Becuase they called me up and said "You know, they require a certain type of Tranny fluid. We had to get it from out other store." It was $9.99 a quart.

Crazy. So I think they did. Thanks!

Damn, thats how much they sell them at the dealer. Buy them from a Toyota dealer for 3-4bucs.

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Well, I got the car back. It does not seem to run much better. Any thoughts?

Could it be the transmission itself? Could it be the brain? Electrical? I'm really at a loss now.

The symptom that has become more prelevant is not the "OD off" light blinks on and off steadily on my dashboard.

Thanks!

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Could the torque converter possibly be sticking, or going out?? Just thinking outloud. Do you get a fuel smell from the car, like maybe your cat's are clogged up and preventing the car from revving up? drive it a little, and then look under the car at the catoletic converters, are they glowing red? I'm at a loss amigo. I'd say have it professionally checked out...by a LEXUS shop..not the dealer. On a 1990 model, they'll tell you anything to get you trade it in and buy a newer one.

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Hmmm.... I don't think it is the tourque converter... it really feels like a transmissions thing. But... I have always taken my car to the dealer. Is there anyway of finding a Lexus shop in my town of Albuquerque New Mexico?

Thanks for the post nc11.

It is just a weird problem. I still think it is the tranny or something electrical. Please keep the thoughts coming. I need all the possible diagnoses I can get.

Thanks again!

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Any new thoughts?

If none... how should I get this diagnosed? Without having to pay an arm and a leg at the Lexus Dealer...

I have the same problem with my 1991 LS 178,000 miles. Its intermintent and only does it when its real Hot out (90degrees) and the car is fully warmed up. I also just replaced the transmission fluid and the transmission filter. However, I used Dextron III fluid( the valvoline website says the dextron III is fine for this car, but not totally sure). What I think is happening is the transmission is shifting from first gear directly into 4th gear instead of going to second and third.. I am assuming the computer must be gettting bad signals from some sensor to cause this to happen, or a problem with the valve body. I need help on this issue also, I dont want to pay the Dealer more than the car is worth to get it fixed.

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Yeah!!!

Shifting straight from first to 4th. That is exactly what it feels like.

Can we just replace the brain?

This is where I need help also, I have the repair manuals so I can see if there are any codes that the transmission is putting out. I can only guess that the throttle position sensor or other such as the temperature sensor may be malfunctioning, or the transmission computer. Ill do some more homework to see if I can isolate the problem.

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Hey everyone!

I was curious if I could get some help.

My Car:

1990 Lexus LS400

225,000 miles

My transmission (I believe) is being very jumpy. When I accelerate... the tach will go up just fine in first gear, but as soon as it shifts, the tach stops at 2.2 RPM's. And no matter how hard I press the gas pedal or even if I punch it, it will not move, I have to take my foot off the gas pedal, then wait a couple seconds before it can accelerate again.

This happends about 3 out of every 5 times the car goes through second gear. Anyu ideas? Tranmission? Brain? Chip?

Thanks in advance!

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I Just got a breakthrough. I Have the same problem, and I just checked the codes on the diagnostic port for the transmission and I have a Code 63. This means that solenoid valve number 2 has a short circuit or Open. When this happens the transmission goes into Fail safe function and directly shifts into Overdrive (4th gear). I bet I need to replace solenoid number 2, the electrical cables or the ECU. I an sure the solenoid itself is bad.

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Isnt the internet great!! I just found the Part number to solenoid number 2 its

(8542050020)(same part number as solenoid number1) at lexus its $229.00 list and toyota has the same part and its $199.00. I will try and replace it this weekend and see if it solves the problem on my car.

If you have the repair Manual, you can get the error codes from the transmission and see if you have the identical problem. On yours it could be solenoid number 1 or Number 2.

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Most times all you need to do is remove and clean the solenoids sa they get small bit of debris causing it to not open or close the channel completly to reroute the fluid as intended.

Becareful when removing the valvebody to not let any clips or check balls fall out of place.

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