TBSS problem with ECT

[briandudley1]

I just replaced the engine. I had a very well known reputable tuner log in and set up all my settings, but I am having a problem with code p0118, high ect voltage. I installed a new ect sensor and still getting the same error. I dipped both sensors in progressively warming water and I see resistance dropping likebi think it should.

I pulled the new thermostat and also tested it. It opened when it should.

Not sure if it matters,, but when I look at the book, it says the wires should be yellow and black. Other internet searches say the same thing. On mine, the wires are purple and black.

When I test voltages on the wires, I see 5v on the purple and almost nothing on the black, so I don't think it is a short.

Also, if I clear the dtc's, the temp gauge will jump up and read 210, or whatever the temp should be, for about 1 second, then falls back down.

The e-fan is coming on after a few minutes idling and clearing the dtc, so it seems like it is getting some data. I did confirm the lower hose is getting warm, so I know the thermostat is working correctly also.

I am pretty new to the HP tuner software, but in VCM scanner, it seems to be showing the correct temperature. Ect voltage does not register.

Where do I go from here?

[blindsquirrel]

I would love to be able to tell you which pins at the ECM to check to verify you have the right pigtail plugged into the ECT, but it seems you failed to mention the year.

(is 'TBSS' the new 'Denali'?)

[briandudley1]

Lol, sorry about that. It's a 2006. If I knee which pins to check, thar would be a huge help. I have not been able to find a good pin out yet.

[blindsquirrel]

E40 crew represent!

Erm... sorry. There's so few of us these days. E40 people, I mean.

https://i.imgur.com/WU1c6o7.png

[briandudley1]

Awesome, thanks. Printing this out and hanging it in the garage.

[briandudley1]

So that was a huge help. Hoping you can help me a little more. It looks like pin 55 should be my ECT. I confirmed that it is in fact yellow out of the harness plug. So my question now is, what is the cable I am plugging into the ECT sensor and where did my ECT sensor go. The plug wire is only about a foot long coming out of the harness very near the ecm. It is a purple wire and black wire. Fits perfectly into the ECT. I tried to check continuity to the ecm plug, but it did not seem to pin out to any of the pins on the connector.

https://imgur.com/r2hCVRK

The only other errors I have seen so far are brake sensors and O2 B2S1. A little back story, The engine and trans have been out of the car for 3 years. Rebuilt them both and just now putting them back in. I labeled all the connectors, but the labels faded or fell off, so I am pretty much guessing based on plug location and fit.

[blindsquirrel]

20210508_214125.jpg

screenshot.08-05-2021 21.48.37.png

The only thing I can think of that's close by is the purge solenoid, but the colors are wrong, and it would be a bit of a stretch to get them swapped. It's hard to find things like this in the manual being that connectors are separated out into the relevant sections. If you don't know what a thing is there is no way to know where to look for it in the manual. Brakes? Exterior lighting? Horns?? WTF!

If you find the actual ECT pigtail and what it's plugged into, that's where your PU/BK pigtail will go.

[blindsquirrel]

Brake fluid level switch.

[blindsquirrel]

20210508_223613.jpg

[briandudley1]

You are my hero. I have been chasing this for 3 days. That knocked out 2 problems. I never even saw that plug on the MC until your picture. Once I found that, I found the ect plug just hanging down right next to the ect. Thank you so much.