Failure To Shift Into Overdrive

[paca444]

Let me start out saying that I live NY, and the weather varies quite a bit from one season to the next as you might imagine. Consistently, my 1999 es300 needs to warm up to about half of the operating temperature to shift into overdrive. After it has shifted, all is well and you would never know there is anything wrong. In the winter however it takes much longer to finally shift into OD. After 120,000 miles, it finally stopped shifting into OD all together. A possible related issue is the CEL coming on for a lean mixture. This issue comes rarely and normally just goes away (the bucking and CEL light that is).

I found a post from the past that seems like it might be what I have but the poster never said what part it is...

"Lexus01,

Thirdly, the transaxle is designed to not shift into overdrive until the transaxle fluid has reached 152 degrees. This is to prevent premature wear in the tranny and get the engine up to temperature faster so it meet emissions requirements faster. If this concern is particularly noticeable in colder weather, this may be the problem. Note: please make sure the fluid you used in the tranny is the Toyota T-4 fluid. According to the engineers, the wrong fluid will lead to slippage and possible failure.

The only oddity is the general misfire code(p0330). This could be an entirely different problem, or ist may be related to the dumping of too much fuel into the engine.

Let me know how you make out.

Good Luck

Lexasm "

[paca444]

Oh, and to top things off I just found out on ...msn I believe, that the mass airflow sensor would have been covered by a good will warranty extended by lexus when I originally bought the car. The same warranty would have also covered the $400 I spent on getting the charcoal canister replaced. I didn't get the work done at a dealership. Is there any chance lexus will repay me?

[Rhoderman]

Lexus repay you? I doubt it, but you could at least check for sure with them.

For your problems, it sounds like you've lost a temperature sensor in the engine, or it is not working correctly. The computer uses the engine temperature for both things you mention: shift into O/D and fuel mixture.

For the tranny, it is just as your quote stated, to allow the engine to reach operating temperature faster.

For the mixture, as the temperature changes, the engine requirement for fuel changes as well.

You say it seems to be running rich and throwing a code, and it doesn't shift into O/D like it should. I'd at least check the resistance of that sensor. You might also have a bad (stuck open) thermostat which would cause it to run a lot cooler.

Good Luck, and let us know what you find!