lexgoez

Cant seem to figure out what the issue is. The OD turns on and off. When the engine is cold, theres no problems with the shifting. The OD also stops working when I come to a complete stop but will work fine if I just keep driving after turning on the car. There are also no codes. Many of the forums say it could be the knock sensor. Cleaned out the IACV but it seemed to be ok. Changed the tranny oil a few months ago, didn't seem very many metal shavings. The issue started when the car wouldn't stay on, so what I did what kept my foot on the gas so the car wouldn't die until I made it home from work. If anybody has a good idea of what could be wrong please let me know, I could really use the help. Thank you for reading

Drcoffee

Check the MAF. It also affects the transmission shifting. But from other threads, inability to stay in OD usually was a sign of transmission failure.

You can unplug the MAF and drive it. If it has no impact on driving, then its probably the problem.

The knock sensors will throw a code

lexgoez

Thanks drcoffee Ill be sure to check out the MAF, I had thought about cleaning the MAF this weekend to see if it makes a difference, I hope there will be other suggestions as to what else I should look at, hopefully its not the transmission

salimshah

Welcome to CL.

RX locks out overdrive when the engine is cold. This helps in warming up things quicker. Driver has to exhibit restrain by keeping rpms below 3k till things warm up.

Make sure that the self test ,, moving Key from ACC - to -run (step before start) ... stay in that position for few seconds and see the CEL and other warning lights do turn on and after start, they turn off.

Please read the owners manual. Sorry for harping on that.

Salim

lexgoez

Hey salim thank you for replying, harping in is what i need so i can try to fix the issue, i was unsure as to what ur comments were referring to, but are you saying that when i drive the vehicle i should try to keep it under 3k rpm, the car seems to be shifting at a little just above 2k for the first two gears, then the 3rd shift normally doesnt take place, i was also unsure what the self test was for, is it so i can see if my car is picking up codes, please let me know, thank you

salimshah

The selftest ensures the ecu is working and warning lights are not popped.

Watch the temp gauge. Normal operating temp is usually around 1/2 way. One should try to keep the rpm below 3k till you reach that point.

Have you had the RX for long?

Salim

lexgoez

Ok ill do the self test to make sure everything is working. I could try to stay below 3k on the highway but then id be driving around 60mph on a 75 mph highway, No salim i havent had the vehicle for too long just about 8 months, please let me know what else you think i could i could check, once again thank you for replies, all your threads have always helped improve my knowledge of lexus vehicles

lexgoez

Hey salim, i just did check and realized the CEL does not turn on, i only
See the oil, abs, door, brake, seatbelt, and battery light on, does this mean the ecu could be bad or just blown light bulbs, please let me know what you think

salimshah

Most likely the bulb is blown.

Look for the DIY on changing the "D" bulb and although the CEL is a different bulb, but the access is the same.

You can have the ECU read at auto parts store and we can then go from there.

Please read the Owners manual.

You should try to remain below 3k and stay in the slow lane. Exception would be for the safety.

Salim

lexgoez

Alright sounds good Salim, already on top of the bulb change DIY. Hopefully codes pop up so I can begin to diagnose the specific problem. Ill keep you updated but so far thank you for all the effort you've put in. Ill do my best at keeping the vehicle below the 3k mark

lexgoez

Hey salim did a read on the car and turns out it had several codes, the 3 turned out to be p0330, p0125, and p1135, the afr sensor and coolant level i can fix, looked at diy for the knock sensor but it seemed too difficult for me to do, if im able to remove the throttle body and intake manifold is that good enough for getting to the sensors, i wished there was a step by step video of everything i have to remove or someone to tell what i need to remove, just a quick question, how long can i drive with the knock sensor being bad, it has been driving bad for the past 2 months or so, just worried about the money issue right now

Lexmus

A knock sensor workaround fix can be found here:

https://www.clublexus.com/forums/rx-...ck-repair.html

My car hasn't thrown the P0330 code since doing this.

Note that this will only work as long as the second knock sensor is functional, and as Salim has posted in that thread, it is potentially illegal in certain jurisdictions.

salimshah

Read up on the knock sensor and you will find that the problem (lock out gets more frequent). Since I have a code reader, I could reset it and the right solution is to get it fixed.

Good state of Texas requires no modification can be made to defeat/trick emission. Other states would have similar laws. I can only recommend proper and legal fix. DIY is pretty detailed and I made sure not to skip any important step. The good thing is that it does not require any special tools and no heavy lifting. Most fasterners are hand tight.

If some one sold you the RX with the CEL defeated, you may have a recourse specially if it was a business.


Salim

lexgoez

Thanks lexmus, the hack seemed to work and OD now kicks in every time, but now theres knocking, i did drop from 91 to regular gas a few days ago but just switched fuel lvls recently, i hope the hack didnt cause the knocking, happy that OD does work again though

Lexmus

The workaround is only for suspected bad sensors/wiring, not when engines are truly knocking. If even with supreme gas you have knocking, add some octane booster to your tank and see if that helps.