Testing integrated relay

NO. BAD assumption.
Is this in or out of the car ?
What function and range is the meter set on ??
Sounds like you are in way over your head.

 

He was a bit less snarky than others may have been. You guys were cutting his azz because you misunderstood the diagram and didn't understand what he was trying to say about connecting power. I think he went easy on ya!

 

THIS.
Another case of asking the wrong question in the first place.
And people ranting on and on, even after the discussion should be "reset" and started over.

 

Check post 20

 

Here is the entire procedure for testing for excessive O2 heater current. Given the situation, I would focus on the sensor and the splice that may have been made. If a mechanic did this work, I would take it back to them. Some would question the sensor especially if it was not original Toyota.

 

So did you run through all four tests in the procedure? Obviously the thread started out with the closed efi contact resistance measurement of step #2, but how did the other three tests go, starting with the sensor's heater element resistance of step #2? I know you said it was in specs.

 

Here is a totally different perspective where the author states that the air fuel ratio sensor in front of the cat can be at fault creating a too rich condition the rear sensor codes on. I assume that one was replaced as well? Toyota Prius P0138 Trouble Code Finally Solved, The Results Blew My Mind | Torque News

A good scanner that can graphically trend the sensors often tells the story.

 

I just replaced the downstream O2 sensor with Denso and cat with Auto Shack on my 2006. That removed the two codes for the bank 1 sensor 2 related 2 downstream codes. Still throwing the P0031 code and P2238 AF Ratio sensor low pumping current circuit related code.

What's baffling to me is how the sensor operates internally, at least first comparing with the gen 3 similar AF Ratio sensor where the Inspection document notes a resistance for the HT+ and AF- as being 10Kohms or higher.

So, I tested my salvage yard Denso looking sensor and appears to be within spec ~2.8Ω if using the gen 3 inspection document for the Air Fuel Ratio Sensor. I just went to the local Autozone and tested the 234-9056 connection and am getting the same results in spec ~2.5Ω, albeit slightly lower heater element resistance. Both HT+ to AF- sensors don't show a reading no matter how how I go so like open is OK I'm guessing.

Maybe there needs to be another like combustion exhaust gas with high enough temp condition to verify the AF pins results like I don't understand right now. Seems open testing. I'm probably over thinking and want to know how the AF pins sensor operates.

Reads like the ACTIVE TEST A/F CONTROL operation inspection procedure needs to be performed.

Wondering, what's the "hand held tester to the DLC3"?

If the "hand held tester" can be a Techstream, or reads all the ECU codes equivalent enough to Techstream, OBD2 reader, what's the DLC3?

Can Techstream somehow read and display the same data as the "hand held tester?"

Higher temp, maybe higher resistance, though reads out of spec. from what I'm reading seems.

I think I have everything document wise for my situation P0031 and P2238 codes where:
- For P2238 is titled "Diagnostics - SFI System 05-327"
- For P0031 is titled "Diagnostics - SFI System 05-79"

O2 and air/fuel ratio sensors | Page 2 | PriusChat

What threw me for a curve was first reading the gen 3 upstream sensor "Inspection" document that I'm not finding at the moment that I think @Patrick Wong posted.

Anyone know of a quick check or method they found to narrow down?

 

Data Link Connector 3 is just the thing under the dash where you plug your diagnostic tool in.

 

Wow, albeit I don't have much (OK none) blonde hair left as it's all decided to fall out, I feel a blonde moment. I'll try to re-read the document a couple more times when I'm not all doing body work.

 

Why does that part say "made in china?"