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Skyvisions, ASE Certified Technician
Category: Lexus
Satisfied Customers: 14445
Experience:  Lexus Expert
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2000 Lexus RX300 V6 Tranmission wont shift into OD in cold

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2000 Lexus RX300 V6 Tranmission won't shift into OD in cold conditions. Check engine light is on most of the time and I've changed out bank 1 O2 sensor, throtle position sensor, and cleaned air intake sensor, and changed air filter. Any ideas?




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What are the malfunction codes that are set in the computer that turn the check engine light on? Does it ever shift into O/D if you get it on the highway?




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Customer: replied 8 years ago.
The last code was something to do with air intake sensor, but I don't have the code now. No, it doesn't shift after I get warmed up and at highway speeds. It doesn't do this all the time and I can't see a corralation between the check engine light which is on 75% of the time and the OD not working. I do see a corralation between the Cold weather and the OD not working. I had a 1999 that did the same thing but after it warmed up it would shift in to OD. This is not acting that way at all.
Customer: replied 8 years ago.
I have an account with money in it but am not sure how to access it. Is this what is holding your responce up?

It is going on 1 AM here EST. I need to process this info and get back to you tomorrow. Is this acceptable? If you can get the code number that can be very helpful. Most parts stores like Auto Zone do free code reads.


Let me know how you would like to proceed.



Customer: replied 8 years ago.
ok. I'll try to get a code.
Customer: replied 8 years ago.

codes are PO300,302,304,306



Short term fuel trilm1 7%

Long term fuel trim 1 -6.3%

ST fuel trim 2 19.5%

LT fuel trim 2 52.3%

ST fuel trim 3 -100.6%

LT fuel trim4 -100.6%

The p0171 is a lean code and the p1150 is a malfunction in the Bank 2 Sensor 1 AFR sensor. The other 300 series codes are misfire codes for the front bank or bank 2. The O/D problem is secondary to these problems. The O/D is temperature sensitive and will not engage until the computer sees the proper coolant temp input.


You need to determine if the AFR sensor is bad and is driving the system lean(not enough fuel) and setting the P0171 code or is the system running lean (intake leak, dirty or contaminated MAF sensor) and the result of this is making the AFR sensor stick with a high voltage and triggering the P1150 code. There are some test that can be done to determine this and one involves using an active testing scan tool. You need to determine which is the cause and which is the effect so to speak. The most common problem is a dirty MAF sensor which makes the system run lean. The only thing that kills this theory is that it usually affects both banks not just number 2. This only leaves the AFR sensor which is also common to go bad on these engines. Focus on the tests for the AFR sensor. It should read 3.3 volts which is equal to 14.7 to 1 fuel ratio. If you shoot some carb cleaner in the intake the voltage should drop immediately on the data list. If you create a vacuum leak it should go up immediately. If it does not and stays fixed then it is bad.



Skyvisions and 3 other Lexus Specialists are ready to help you
Customer: replied 8 years ago.
I'm sorry for the delay in getting back to you, I was gone for a week. Can you tell me what AFR and MAF stand for?

AFR is (Air Fuel Ratio) MAF is (Mass Air Flow)


The AFR is basically a new version of the old O2 sensors.


The MAF is the device that determines the amount of air flow into the engine.