Help for P011B coolant temp CEL--Dealer can't fix!

Hello.

I have Gen3 [2013] Prius that has a P011B error code CEL that the dealer can't fix.

After replacing the coolant sensor, the CEL still keeps showing. Over winter it was off mostly. Now it's warmer and it's on mostly [sometimes goes off for a couple of days and then back on for weeks]. Dealer said the code means there is a discrepancy between the coolant temp reading and the air temp reading during the initial start-up readings the ecu pulls.

Initially the dealer said the coolant sensor was faulty and replaced it. I took it back to the dealer when the CEL came back on a couple days later and the service adviser, service tech, and service manager took me into the service manager office and they told me what service diagnostics they had done and that they couldn't fix it. Period. My car is out of warranty, and they don't know how to fix it. Good news was that the CEL is reflecting incorrect readings and it is not a danger to drive with it on for this code. But the car still has a CEL on on the dash and it may hide some other problem.

Here is what the service tech said in the notes of the follow-up repair invoice [which is what they told me they had done]:

"93402 P011B stored 1.50 hook up techstream and pull codes. Same code was present, P011B. Performed inspections of sensors, both reading normally at this time, 150 air temp and 142 coolant temp. Disconnect sensors and temps drop to -40, indicating open circuit which is normal. Opened TAS case and discussed with engineer. May have issue with Air Temp sensor since air temp was reading 105 degrees at cold start up and coolant temp was 55 which seems normal and most likely ambient temperature. Would try Air Temp/Mass Air Flow Sensor as next stage, although TAS shows case where this DID NOT repair vehicle."

Is there someone who can give me some advice about this?

Should I try replacing the Mass Air Flow sensor?
Should I try an ECT spoofer?
Should I try a couple sticks of dynamite?

Thanks, MichaelRogers

 

Hello. Thanks for the response. Car has 105k now. Problem for awhile now. Car is in Santa Fe, NM. Dealer is Toyota of Santa Fe. Car had a fender bender before I bought it, not on CarFax. Called Toyota corporate and they could do nothing--out of warranty. Did offer $750 discount on purchase of a Toyota in future. Any ideas?