01 V8 Knock sensor wiring

Sat on my dad's farm too long and mice chewed up the knock sensor wiring.
I got in and cleaned it up. Purchased new wells knock sensors and a new harness but the original had no quick connect, so I had to solder it in grey to grey and black to black

However, brown only exists on the sub-harness so I looked at the diagram and soldered it to the shielding around the other two wires

but after it was all put back and running it still coded on bank 1 no matter how I cleared it, code always came back. I've got it back apart and I found diagrams that indicate that the brown from the knock sensor sub-harness goes to ground point e4 but I have no clue what that looks like in real life. Is it a spot on the wiring harness? Is it a spot on the block?

 

Honestly I can’t even tell from your photos what is happening; but if you need to ground your 3rd wire and that’s what you’re asking, just run an extra wire back behind the block and attach it to a ground or find one along the fender to attach it to; I’m not super familiar with the first gens so I can’t tell you exactly where that ground is but one of the guys here might chime in

 

Also that shielding most likely isn’t grounded, probably shielded to prevent melting or electrical interference

 

I'm unsure why you would say you can't tell what is happening but I'll try to clear it up. This is what an '01 v8 tundra looks with the intake manifold off. With the area cleaned up you can see the starter and the knock sensors. Notice that bank 1 knock sensor is not wired, it was chewed by mice (a common issue on these models). I stripped back the insulation on the wiring that the knock sensors were connected to. The blue/yellow insulation contains a grey wire with shielding around it. the blue insulation contains a black wire with shielding around it. I purchased a knock sensor sub-harness from rockauto as well as knock sensors. I replaced the knock sensors and soldered in the knock sensor sub-harness to the wires that were going to the knock sensor's previously. Grey to grey, black to black. However, brown only exists on the sub-harness so I looked at the diagram and soldered it to the shielding around the other two wires. This did not clear the code. I suspect that the brown from the knock sensor sub-harness goes to ground point e4 but I have no clue what that looks like in real life. If there is a harness I have not seen any pictures of that and it's not easily accessibl e or visble, but I will continue to search.

 

This is the knock sensor sub-harness I got. More Information for WELLS 1P2619
I'm starting to think I should have just gotten - More Information for STANDARD MOTOR PRODUCTS S2545 and not have to worry about a ground.

 

The shield is only to protect the knock sensors from electrical interference/noise. Unless it’s touching bank 1 sensor signal wire, you should be fine with your solder job.

The P0325 means you have an open or short in that sensor signal wire back to the ECM or that new sensor is not good.

 

I think Toyota sells a complete knock sensor harness.

 

For the earlier years, I believe this is true.

For VVTi trucks like mine, not so true. I wish it was a thing, I really want to replace my bank 1 sensor and harness. I may just end up being my plastic connector that's squirrely.

 

How could I test the sensor?

 

give me year make and model and there should be an ohm value for the sensor that you can test

 

In the FSM for the sensor they show testing with an o’scope

 

I've seen folks on the 'Tube test function by attaching to the leads and tapping the sensor with a hammer to see if the sensor outputs. Last time I saw someone do this was on the Project Farm channel, where he was resurrecting a Honda.

 

I think it’s like 120-280k ohms at 68 degrees

 

I think they're for the later years. It comes with a plug in on the end that I had to cut off and splice into mine. We don't have that plug on the earlier models. Still works good though 8 years later.

 

I've been full-on, inside and out of the EPC, and scoured Google. I can't find a complete sub-harness or individual end-to-end harness for the 2005-2006 Tundra V8 knock sensors.

I've found a sub-harness for earlier years, but drawing a blank on which years. It has the plugs for both knock harnesses and the starter, and I think a ground tee that mounts to a bolt hole in the valley/top of the block, and I think it connects toward the back of the valley, near where the intake meets the block, possibly beneath the crossover housing.

I'd need to go down a painful path to try and find that damn thing again, to figure out what year it's for.

 

Yea I see a few spots where I can toss a bolt in and ground. I think I'll toss the other sensor in bank 1 and put it all back and see where it lands. Getting good at taking the manifold and evap hoses off. By the end of this I'll be able to do it with my eyes closed.

 

That was going to be my next suggestion, if the part number is the same, swap banks. If it stays on one side, it's the wiring.

I know both knock sensors use shielded wire, I'm quite certain what you're referring to as "ground" is actually shielding. Looks like you're treating it like coaxial/RG6 cable, I don't think it should be.

 

Students are starting to show up, but I have a pic on my very first thread of that connector. I'll dig it up later.

 

Maybe it's this thread?: https://www.tundras.com/threads/is-it-worth-it-long-read.30954/

 

This may also help: https://www.someguyinnevada.com/toyota-tundra-starter-repair-a-journey-of-discovery

 

Yup. This is the connector in question.

 

That connector looks very similar to the one I purchased on rock auto; However; he does not mention where the quick connect location is. I have posted asking if he remembers.

 

AH nvm he does mention he had to splice into it

 

You got it homie. There was nothing back there, in there, anywhere around there. Gotta do what you gotta do.

 

I sent it like this after swapping the bank 1 and 2 sensors, and moving the brown (knock sub-harness) to a bolt on the fuel rail. Still coding after clearing and driving around several times. My next plan is replacing w/ OEM sensor and remove the Sub harness and replace with simple connectors and that will remove the brown issue altogether. If that works I'll replace the other sensor and hopefully we will be set.

 

Denso is the OEM manufacturer of those sensors. Go buy Denso brand sensors, without the Toyota box and 30-50% upcharge. Just don't be stupid by ordering them from scAmazon, fleaBay, WallyMart, Sears, Home Depot, Temu, or otherwise. You'll get authentic looking product, which will be anything but.

Then use the money you saved to buy new OEM pigtails specifically for your VIN. It should make wiring easier, if the OEM pigtails are color-matched.

 

Agreed. I ordered the harness straight from the stealership. Didn't think to get a part number back then but it was like $50 with no sales or deals.

 

I'm going to try a vulture shop, those OEM sensors are too high specially considering that I'm still unsure if that is the cause. I'm kicking myself for tossing the old ones, lesson learned there!

 

I never toss old parts. I usually hold them for a year or two, esp. if they're questionable on being bad.

Not saying to buy OEM. Buy Denso brand. They are the OEM manufacturer, but much cheaper than buying from a dealer. Just don't buy them from a sketchy place that's known for counterfeit parts (scAmazon, fleaBay, WallyMart, Temu, Sears, Home Depot, etc.)

But seriously: Buy new pigtails from the dealer, so hopefully you get wire-color-matched harnesses and the method of wiring makes more sense. It's OK to get the part number from the dealer, just don't buy it directly from them. Instead order it thru https://autoparts.toyota.com so you can cash in on up to 50% discount, and if your local dealer supports pickup from that National Toyota Parts site, you still save the money, it's savings you don't get otherwise.

This is one of those parts where, it's such a pain in the ass to get under the manifold - tedious, at best - just get it done right with the right parts the first time, and 'cry once', you know?

 

Can you find a link for the denso? I searched for a while and couldn't find anything.