Emissions Test Fail

You can believe the code; you can't believe what it "says".

P1 codes are in a range that is "manufacturer defined". A code in the P1 range can mean completely different things from one make or model of car to another. In a Prius, P1116 has to do with the coolant temperature at the outlet of the thermos bottle that is used to keep it warm while the car is off. You can read more about it here, or of course in the best resource you can use, the repair manual (more info).

When you use a thing to read the P1116 code and the thing says "Evaporative sys, O2 sensor", you just have to ignore what it "says". It is throwing random things at you that the same code might mean in completely different cars.

 

See
What's the Toyota Prius code p1116?

P1116 on a Toyota Prius is an OBD-IiManufacturer-specific code for a voltage issue with the engine coolant sensor in that the signal being sent to the engine computer is not within the range set by the manufacturer. Second-generation Prius, model years 2004-2009, has a 3-way valve to control coolant flow between the engine, the hot coolant storage tank, and the heater core. It is involved with heating the passenger cabin, as well as reducing cold-start emissions.If anything on Prius has to do with emissions the check engine light will illuminate; if something goes wrong with this valve, the light comes on. The control valve is prone to seizing, and Toyota has issued a technical service bulletin (TSB) on this problem.

 

The PriusChat post linked in #2 gave a little more specific information.

What really specifies the "meaning" of a trouble code is the "DTC detection condition" shown on the first page of its workup in the repair manual.

P1116 can be set for either of two different conditions: (a) the thermos temperature sensor didn't even rise more than 3 ℃ during the recovery cycle, or (b) it rose, but was still not within 25 ℃ of the engine coolant sensor by the end of the cycle.

The troubleshooting steps that you find for it in the repair manual (see the other link in #2) boil down to first figuring out which of those two conditions set the code, and then figuring out what caused that condition.

 

Well, have you checked the coolant level? Is it low?

I'm not sure offhand whether I could definitely rule that in or out of the picture, but it's one of those things that takes less time to check than to wonder about.

 

Where ever you take it to has to have a capable scan tool to properly diagnose this system. This could be a fault with the temperature sensor, or the electric coolant pump for the storage tank (or maybe the 3-way valve).

The shop had to be able to see the data from the ECM and be able to command the pump and valve if they are going to fix it the first time.

Posted via the PriusChat mobile app.

 

If you register your 2006 Prius in Northern Virginia is exempt from emissions. Other hybrids or conventional cars still need emissions.

 

Must be a Langley employee perk

 

Maybe they lobbied for the law! However, for 16 years now I renew my registration without emissions on my red 2006 Prius. I had also a green 2006 Prius same thing but on my 2013 hybrid Lexus I have to pass emissions every 2 years.

According to the Code of Virginia a “qualified hybrid motor vehicle” is exempted from the vehicle emissions inspection requirement if it obtains a rating from the U.S. Environmental Protection Agency of at least 50 miles per gallon, or 48 miles per gallon for model years 2008 and 2009)