This is the engine harness side of the connection to the knock sensor pigtail. I will referr to the terminals as yellow and red per the picture below:

Kinda looks like a
anyway, If I shine a flashlight inside connector I can see the following markers
Yellow=6
Red=B3
My question is this: Which terminal is supposed to be the signal from the knock sensor and which one is the shielding ground? I am currently working on making an adapter from early style to late style (using an engine from a 91 in a 94 and don't want to butcher the harness). I removed the pins from connector without making a sketch first. I know STUPID. Thanks in advance, I've done alot of searching on this and just haven't found what i need.

 

No idea just probe it at the ecu?

The piezo sensor puts out an ac wave form so it's polarity doesn't really matter. I remeber reading that the shielding is only grounded at the one side, so those would both be sensor wires one of which will be attached to ground (along with the shield). Since there is only one input for knk at the ecu, the ecu only reads the positive side of the ac wave.

The 90-95 4runner manual has pictures of all the plugs in the electrical section. "site:yotatech.com FSM all years" I think is the key phrase.

 

My manual ('94) shows a different connector. "EB1" is a 2-pin rectangular sealed connector, like to an injector. Not a round connector.

If it helps, the manual shows the sensor wire is black, and the shield wire is brown. While the "polarity" doesn't matter, it has to be hooked up correctly because it is not a differential signal. The signal is on the black wire; the brown is just grounded at the ecu side and not connected on the sensor side.

Did you check the resistance to ground of the pins? (BR-shield is grounded at the ECU side.) Or do know which wire is which but don't know the position in the shell?

 

Well I already have identified which wire carries the signal (black) and which one is the dead end shield. What I am unclear on is their positions in the connector as checking to ground on either of the knock sensor pigtail produces no continuity (guess the circuit is normally open). This make sense?

 

Already checked the FSM, connector ED1 (the one in question) is not depicted in the last page of the engine electrical with the other connectors. K1 is, which is the single conductor connector at the sensor itself.

 

 

I'm confused. Why are you asking about the harness if you already know which one is grounded. Is this picture of your donor plug? The one you're adding would make sense I guess if you already cut it loose.

You can figure out the polarity of the sensor by hooking it up and probing with an inline diode on the probes, zero volts indicating a backwards connection. Of course you will need to give it something to sense, light tapping or hooked to an engine. And it's best done with an analog meter.

 

The picture(posts #1 & #6) is of my 88 3VZ-E engine wiring harness connector for the knock sensor wire.

I don't know exactly why he wants/needs to know. I just know how to answer the question correctly. So there's no real need to do anything more at his point.

 

Thanks to MudHippy. To answer your question Co 94 PU, I am making an adapter out of the KS pigtail from the late style, and the engine harness of the earlier donor truck. The wires on the later style pigtail are color coded so I easily knew what was what. When I removed the pins (and cleaned them up to accept the new wire) from the early style engine harness, I neglected to make a sketch of the pinout of the early plug. Wanted to get it right before I put this Pig back together. It's all under control now though. thanks guys.

 

Hey Rustybutterknife, how did the adapter you made work out for you? I am currently in the same situation, and am trying to decide how to proceed. I am thinking I want to just splice the wires together, with aircraft grade environmental connectors, or install a 2 wire Radioshucks connector.

I'm guessing this situation only affected a hand full of yota's?
THanks
-Joe-

 

It worked out great. I took the section of wiring that runs through the hole in the intake that goes from sensor to harness from the late engine. cut the wires and completely stripped the shielding wire except for about an inch where it goes into the squarish 2 wire plug. I then used the vehicle harness from early donor truck, the end that would plug into the early roundish pigtail sticking out of the intake. I soldered the signal wire to the signal wire on the late pigtail i prepped previously. I then shrink tubed that connection, wrapped the bare shield wire i stripped earlier around the signal wire a few times and soldered it to the bit of bare wire connected to the round connector. I heat shrinked it in place sort of like the coaxal wire was on the earlier ones all the way up by removing the pins carefully from the round connector but you could more easily use tape here. No codes and runs great. If you have any specific questions post em here. Tried to explain the best I could but i may have left something out. Good luck.

 

Thanks! I had to go a different route, still have not tested it. I bought a 2 pin Molex connector from Radio shack, and installed that. The only junk yard in my area had no 3VZE's, and the other junk yards are 90 miles away. Of the stealership cant just sell you the correct plugs, you gota replace the whole harness!!
-Joe-

 

anyone know where I can order one of these connectors that goes to my knock sensor pigtail from ecm. Tried toyota dealership already

 

OH MY GOD!!! I see the photo of the plug, but not the wire it is connected to, I mean, my engine's harness plugs, both the sensor and the wire were corroded by rats, I don't know the correct wire, and where it goes from or to. The only thing I see is the rest of the sensor wire. Going to replace it, but still don't know where it connects to. Any help?

 

Can someone tell me where does this cable come from, its color, or somethingtha helps me to identify it? I mean, some " chief " had cut the wire. The onjy thing I have is the female from the knock sensor, but I don't find the male where it connects to. PLEASE