1999 ES300 not downshifting
 

Group any assistance would be greatly appreciated.
My 1999 es300 with 147K miles does not down-shift to first gear once warm. Once the car is warm, I will stop and upon starting, the car's RPMs slowly climb to 2000 RPM at 25 MPH. It seems as if the car is starting in second gear. Another symptom I noticed is that in cruise control at 45 MPH it clunks into and out of O/D. Transmission fluid is full and color seems fine. I noticed once that at 30 mph once the car was driving smoothly, the check engine light blinked 2 times then was off.
Once again any help or advise would be appreciated.

Sounds like you have a malfunctioning solenoid or metal debris in the valve body causing problems. Does it go into reverse just fine?

No problem with reverse.
Thank you for the consideration.

What is the service history of the transmission? How did you check the fluid level? Be specific. Have you hooked up a code reader?

I have only owned the car for 2 years and drove 10K miles; so I do not know the history of the transmission. Until recently, no issues with the transmission.
As far as checking the fluid: I drove the car about 5 miles or 10 minutes until it was warm, parked on a level surface, with the car running I checked the fluid level in the transmission. Dipstick indicated that there was sufficient fluid, no discoloration of the fluid.
After your post, I checked the codes and P1150 came up. Air Fuel Ratio Sensor??? Could that be the cause of these symptoms?
Thank you all for the expertise and consideration.

If it goes into reverse fine I would consider the transmission later down the line. Air fuel ratio sensor certainly could be it. Make sure to buy a Denso one and check your air filter too while you're at it.

MANUAL MODE:
This is old school but it works on most hydraulic transmissions.
ECU controls the shifts via solenoids.
Note: SL1 shift solenoid is energized when shifted to any drive position. (1st gear)
If SL1 is failing, trans will engage 2nd gear instead of 1st.
To eliminate the electrical side of it, disconnect the SHIFT SOLENOID CONNECTOR on the trans.
This connector should be just above the park/neutral position switch connector.
Make sure your trans level is correct.
Drive it.
The transmission will shift via hydraulic pressure.
​​​​​​​​​​​​​​I guess perform this test when the issue arises. (warmed up as you stated)

If you have all gears in MANUAL mode, then its in the electrical side you have the issue.

You will likely to have codes after this test,
Just wipe them out after.

UPDATE: I drove the car for an extended period and the transmission issue did not occur. What did happen was the car would intermittently run rough with the check engine light blinking occasionally, then finally it stayed on. I checked the code reader, 4 codes: bank 1 cylinder mis-fire, cylinder 1 mis-fire, cylinder 3 mis-fire, cylinder 5 mis-fire. Do you guys thin it would be worthwhile to replace the oxygen sensor on bank 1 exhaust manifold? The sensor does not look too old, but I guess it could be malfunctioning. I feel that perhaps the transmission not shifting could be related to this.
Thanks for all your assistance.

Hey everyone, not sure if anyone is still active on this but this happened to me today. Car was running totally fine and at red light I notice it was not accelerating over 2000 RPM. I ran through the gears starting at Park then the trans kicked and all was good after that. Any advise ???? Thanks !!

Hello,

This is an old enough thread that most of the people are not present around here anymore, so I would suggest creating a New thread for your specific issue, describing all the details you an think of that can help get to the cause.

Hope this helps and best of luck!

Manual Mode
 

Regarding Nad1370 s post. Is it ok to disconnect the solinoid connector permanently if the tranny shifts fine in Manual Mode? Also can anyone describe or send a picture of where that connector is located are we talking about on the transmission from above or from below?

No, not it is not. First of all, you won't have access to all the gears, O/D included, and other than that, the car will have no way of smoothing down every shift, causing a pretty noticeable jolt, especially if you try to shift the gear with incorrect timing, it can cause some serious damage. And lastly, it doesn't make any sense in your case, if you are missing the First Gear, move the selector to L position and see what happens, if it won't help, there won't be much the wiring could do.

Hope this helps and best of luck!