Transmission stuck in forth gear check engine light is on.

The Check Engine Light is on? Did you read the DTCs.

The second link has the answer, the first link says it is a known issue. It is times like this you need the Dealership or a good auto electrician.

Transmission won't shift to third until temp rise

ClubLexus https://www.clublexus.com > forums > 713188-transm...
Apr 1, 2017 - Transmission won't shift to third until temp rise ... The solution is to drive slow and keep rpms at 2.5k and 3k at max till the engine and transmission warm up.
Sometimes transmission wont shift from 3rd to 4th - ClubLexus
Aug 23, 2021
Won't shift from 3rd to 4th gear - Lexus Forum Discussion
Jan 25, 2011
RX300 not shifting into overdrive. - Lexus Forum Discussion
Jul 11, 2013
FIRST POST! RX300 no 4th gear a full year. Fixes? - ClubLexus
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More results from www.clublexus.com

Owner of Lexus RX300 with 182000 miles. Recently the ...

JustAnswer https://www.justanswer.com > lexus > 3wsxt-lexus-rx3...
Aug 22, 2010 - Recently the transmission won't go into overdrive. Stays in 3rd gear like when you press the o/d button to do so. When car is cold (live in ...
1 answer · Top answer: Hello and thank you for using just answer! The check engine light is on correct?

https://www.google.com/search?q=Lexus+RX300+will+shift+into+overdrive+once%2C+and+after+slowing+down+it+won%27t+go+past+3rd+gear

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could need new solenoids, wiring or computer, cheaper than new tranny

ok first the srs light is on when there is a malfunctioning with the airbag system, need to get that check out, and about the transmission you should check the fluid to see if it is on level of if it needs a flush.
Here is how to do that..
1- open hood 2- by the driver's side on the engine there is a dip stick that says transmission fluid 3- check if it is in right level
if it is not recomend a transmission fluid flush and check transmission
thank you good luck

Hi, a few questions 1st. Did your mechanic check for engine codes? Is your Honda a v-6 or 4 cylinder?
The flashing D4 light indicates a possible transmission malfunction. You should avoid rapid acceleration until the cause of the light blinking is determined.
If you have the V-6, there is a diagnostic port to connect a scan tool to read any stored engine codes that have turned on the check engine light. This port is located behind the ashtray in the center console (most cars did not have this til 96).
If you have the 4 cyl engine, there is a service connector located under the dash on the pass. side. Inside the connector is what looks like a 2 wire plug should be attached. Take a paper clip, unbend it, and insert the 2 ends of the clip into the connector to 'jump' it. Turn the ignition switch to the on position (don't start the vehicle), and the check engine light will flash. Count the flashes, short flashes are for code #'s 1 to 9 (single digit code), a 2 digit code will be a long flash for the 1st digit, followed by a short flash for the 2nd digit. If there is more than one code, they will be separated by a pause. They will repeat so you can count them and write them down. Let me know what the code #'s are so I can help further. Curt

Theres a transmission cooling sensor and somtimes the wire comes loose from other repairs being done around it. or its just out. its on the left side sitting on the tranny. THATS WHY your d4 light is blinking

change the transmission sensor...they are outside of tha transmission

this indicate a transm. failure, begin to check fluid transm. level.

its a transmission trhouble, check if speedometer works, if transm. oil level is ok, maybe this cause this problem

TCU (Transmission Control Unit) Located behind the Passenger Kick panel. it will have a burnt diode inside and can be purchased on ebay for about 79.00 with exchange.

Lugnut61

The D4 light blinking is the vehicle computer telling you there is a transmission malfunction and transmission codes are stored in the computer's memory.The codes have to be pulled out manually unless it has an OBD2 connector.A transmission shop or Honda dealer can pull the codes.