eljaydub

Hi - Hoping you all can point me in a good direction....
2001 RX 300
Runs just fine, nothing out of the ordinary, nothing leaks, no knocking or burning or smells.

81,500 miles and I was just about to put it up for sale (got a new car:-) when the VSC, Check Engine and Trac Control lites came on in the dashboard.

Over the years this has happened before and generally they do something with the fuse and it goes away and comes back years later. This time, it is different.

Took it to local mechanic who has worked on it before....
Did an oil/filterchange, lube, fluids and inspection.

Here are the out of spec parameters from the diagnostic/trouble codes:
-P1130 Air Fuel sensor Bank one Sensor One
-B2796 No Communication w/Key FOB
-Trac Control
-C1201 Engine Communication Error

Replaced the battery as mechanic said low voltage and he thought that might be causing the engine lites to come on and also reason for intermittent key FOB not working.

So, he reset it and advised it should not come on again for at least 200 miles, so if there is something else wrong, won't know until then.

Drove away, no problem, no CEL's on....
Next day took short ride about 2 miles. Ran an errand for 20 minutes, when back out and started the engine and all three lights came back on

So, before I spend any more money (the above was $296.) I would appreciate your thoughts around what might be causing the problem. I may sell it to my friend's dad, but don't want to do that if I can't pinpoint the problem and fix it.

thanks much - Linda

Lexmex

Welcome to the Club

Some of this your local mechanic may or may not be able to fix

B2796 No communication in Immobiliser system
Possible issue areas:
Key
Transponder Key Coil
Transponder Key Amplifier
Wire Harness
ECM (vehicle computer and this one is very unlikely)

The key coil is located right around the the area on the ignition (where you put the key in) and the amplifier is a small box located just behind that area. This is something I would realistically let a dealer or Toyota/Lexus specialist handle (I personally wouldn't touch it myself without additional help unless forced to if that you gives you an idea).

C1201 Engine control system malfunction
This one is the likely reason those other lights come up related to the VSC and Trac as the vehicle computer will prevent their use when this occurs. (Again this would be one for the dealer or a Toyota/Lexus specialist (and has the correct diagnostic equipment) to look at it.

P1130, Air/Fuel Sensor Bank 1 Sensor 1.
This any mechanic can do and we have a DIY for it, https://www.clublexus.com/forums/rx-...el-sensor.html it is the sensor behind the engine (we show photos in that thread of the area).