UnLuckyLex

I can't figure this car out. Looking for good advice. Have replaced just about all sensors and the camshafts actuator. Looking to get this overdrive problem over and done with. Thanks people, really need the help!

LeX2K

Bad thermostat or EFI temperature sending unit can do this the computer won't let the transmission go into O/D until the the engine is at a high enough temperature. If that is not the issue then will need to retrieve any stored codes and go from there.

UnLuckyLex

When I first started the car I have overdrive. I'll reach 45mph and have to come to a stop, it will shut off and not come back on. Is there any transmission sensors that could be throwing codes?

Oro

1st, I have never rebuilt the A541E transmission my TransTec app says your car has. But extrapolating from other rebuilds and service work I have done, I would look at a fluid and control diagram for that particular unit to look for the single point failure for the OD clutch. Usually that is a solenoid.

I would not have, nor continue to, throw parts at this problem until I did that.

I would also have to ask about the condition of the fluid, fill level, and last time it was serviced and with what fluid. I also don't understand how you are verifying the OD works when you are under 45mph while accelerating? Or I am misunderstanding what you are saying.

I am unfamiliar with an eng. temp. feature that prevents OD engagement like Lexus2000 describes, but if this PCU has one, that is a great idea. Is the thermostat working correctly?

UnLuckyLex

I believe so. I can tell the over drive shuts off because of the high rpms. I haven't checked into the solenoids yet. What is called, exactly?

Oro

In most transmission of this generation - 4 speeds of the 80s/90s, it is a step-wise progression through gears. 1-2-3-3+overdrive = 4 forward speeds. C.2000 transmssions (like U151E) is 1-2-3-4- 4+overdrive = 5 forward speeds. these were generally adaptations of existing units and thus the "overdrive" gear as an add-on to make a further gearing reduction at sustained cruising speeds, working only in tandem with the final gear and not separate from it.

If you just accelerate up to 45mph, the overdrive won't engage. So I don't see how you say it's working, then it's not. It should never be working under that speed.

Solenoids are electrically controlled valves. They shunt fluid into different paths to engage different gears. They work in combination to engage different gears. it is not consistent or logical how they work as they work in combination and there may or may not be a single one that controls the OD in a U541E - you'd have to consult the fairly available diagrams to figure that out.

It could be a remote sensor as Lexus2000 said, but I'd look at the control diagram for this transmission (google that) to figure out the likely suspects.

LeX2K

You need to clarify here. How are you judging that you have overdrive? When you first drive the car when the engine is stone cold you should no overdrive, it should only kick in when the engine reaches a certain temperature (usually about 1/4 up on the temp gauge).

UnLuckyLex

I have overdrive because of the low rpms at high speed, but when I slow down under 40 it will cut off and run at high rpms and not come back on for the duration of the drive. It runs overdrive until temp is up to normal operating temperature, then it shuts off and doesn't work and I have 3500 rpms at 45 mph

jenga

Check out this link below and check to see if the selector cable is going bad.

https://www.clublexus.com/forums/es-...d-d-drive.html

RXGS

iTrader: (2)

I don't know if your car is throwing a code, but I remember I had the same issue, shifted fine until it warmed up. For me it was a knock sensor

lostape45

+1 from what 02SDGS said. My issue was the p1349 code for the VVT solenoid and caused the same overdrive issue.

brandon004

Op, did you get this resolved? My dad has a 2000 es300 with 140k (I have a 97 as well) and it recently stopped going into overdrive. After researching this is the only post i found with the exact same symptoms. When i start it up and start driving with a cold engine (it had to be sitting all night) then it will go into overdrive one time. Accelerate to about 45 50 and its in od, but as soon as you have to slow down and stop the next time i get up to speed it will not go into od. And then sometimes randomly it will go away and run normal (although normal operation has been rare). We haven't had codes checked. The check engine and notorious track off has been on since he bought the car.

Does anyone have any info? It would be much appreciated as my dad is currently driving my car to work out of town since he can't take his on the highway!

RXGS

iTrader: (2)

Knock sensor, my car ha the same issue, symptoms, everything.

brandon004

Thank you, how much did the repair run you?

mmatheny

Why does the engine need to be up in temp to go into overdrive? I'm pretty sure my '02 goes into overdrive right off the pop!