p0031 and p1150 - Bank 2 Sensor 1? Or Coolant Clog?

Although I saw people posting repair manual excerpts for other codes in this thread, did nobody post it for P0031 yet?

https://priuschat.com/attachments/p0031-pdf.13255/

No point guessing at what the code's about (especially going as far afield as the inverter) when one can just look it up.

 

It's ok not to know how to do everything listed there, at first. You may need to learn some of it, depending on which direction the early results point. We can always help with specific questions. Learning a few things you might not know yet is pretty much always a better bet than casting about elsewhere with guesses about other things.

You do need to pay attention to details though. The A/F sensor isn't the downstream O₂ sensor, it's the upstream air/fuel ratio sensor. The doc tells you that a few different ways:

• the fortune cookie says "bank 1 sensor 1"
• the hint right at the top of the page says "Although each DTC title says 'oxygen sensor,' these DTCs are related to the air-fuel ratio sensor (A/F sensor)."
• the hint right below the detection condition table says "Sensor 1 refers to the sensor mounted before the TWC and is located near the engine assembly. Sensor 2 refers to the sensor mounted after the TWC and is located far from the engine assembly."

So the code is about the A/F sensor, i.e. sensor 1, i.e. the one near the engine and before the catalysts.

Yes, there is a heater built into the sensor, as shown in the diagram in that doc. There's a picture showing the A/F sensor connector and which pins to measure the heater resistance between, and what the measured resistance ought to be.

There's a picture of the integration relay, and which pins to check the resistance between, and what the measured resistance should be.

When you see a step that says to measure resistance of something, are you familiar with how to do that? Do you have a meter to do it with?

 

Everything ChapmanF posted, plus

"If you have problems with the upstream A/F sensor or wiring (the one on the exhaust manifold, not the one on the side of the cat)"

-from post #6 above.

Posted via the PriusChat mobile app.

 

I should add if the answer is no it's perfectly ok to say so. The more we know about where you're starting out, the more we know about how we can help.

 

At this stage, finding a mini-vci cable (or better) and using techstream (dealer technician diagnostic app) on a windows device might save you some time and parts (money), or dealer diagnosis (money). You can also emulate the OS if you don't have a native device for such.

It might've been covered in post #13, though the link in that post could contain an outdated workup for the above DTC.