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EWD discrepancies

Stuckinthe80s

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Can anyone tell me why there are random discrepancies in the same electrical wiring diagram? I'm listing out all of the connector pins on the associated wires for my 2uz swap, and ever so often I come across something like this:

IH1-1.jpg
IH1-2.jpg


The actual wire on the actual plug is grey:

IH1 connector.jpg


So why would the EWD show two different things in the schematic? For reference, the "GR" wiring is associated with the O2 sensor circuit and the "R-Y" is associated with the dimmer switch circuit for the high beams.

I've got a wire tracer ordered so I'll know for sure soon by tracing it out but I don't understand why Mr. T would label things like this.
 

DaveInDenver

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I'd have to assume it's a typo. Obviously the grey wire is correct for IH1-2 because that's what actually is. Is the red-yellow maybe in position 12 or 20?

BTW, the FSM and EWD are not infallible. There's a mistake in the 2005-2015 Tacoma FSM that may span several years books. The torque value given for the u-bolts on the rear springs is 37 ft-lb and various conclusions are drawn but my thought is it's probably transposed and supposed to be 73 ft-lb.

So you should engage the "does this seem right" filter.
 

Inukshuk

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I'm intrigued by this "wire tracer" tool. Never heard of it. I have one gremlin it might help with. Following ...
 

DaveInDenver

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I'm intrigued by this "wire tracer" tool. Never heard of it. I have one gremlin it might help with. Following ...
If you have a multimeter you already have one. It's the continuity function. Clip one lead to the source or termination and use the other to probe listening for the beep.

An actual wire tracer is handy being smaller and usually giving a visual indication. But functionally it's the same thing.

 

Cruisertrash

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@Stuckinthe80s I've run into a discrepancy in the 60 Series wiring in the Body & Chassis FSM, too. Can't recall what it was off the top of my head, but some poking around with a DMM sorted it out pretty quickly.

At some point I want to make a really long alligator clip test lead, like 10-12', for checking continuity on long wire runs through the body. From the fuse panel to the rear lights for example. It would probably give inaccuracies for voltage or resistance measurements but would be just fine for making sure I've got a continuous wire - especially since they sometimes change color at a connector.
 

Stuckinthe80s

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I'm intrigued by this "wire tracer" tool. Never heard of it. I have one gremlin it might help with. Following ...
1642186115496.png


This is what I bought. I had something similar years ago when I did IT-ish work. It basically does the same thing a dummy light does like Dave said except you can be a lot further away. Also, it kinda acts like a detector where you don't have to even make contact with the wire you're looking for so it's helpful for quickly identifying what bundle the wire you're looking for is in and then you can sort it from there.
 

Stuckinthe80s

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I'd have to assume it's a typo. Obviously the grey wire is correct for IH1-2 because that's what actually is. Is the red-yellow maybe in position 12 or 20?

BTW, the FSM and EWD are not infallible. There's a mistake in the 2005-2015 Tacoma FSM that may span several years books. The torque value given for the u-bolts on the rear springs is 37 ft-lb and various conclusions are drawn but my thought is it's probably transposed and supposed to be 73 ft-lb.

So you should engage the "does this seem right" filter.
Good to know. I saw something similar on the combination meter schematic where it listed a blank and in actuality, there was a wire there. Don't they have proof readers in Japan? For someone who can barely spell ECU, this type of typo doesn't help.
 

DaveInDenver

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View attachment 101026

This is what I bought. I had something similar years ago when I did IT-ish work. It basically does the same thing a dummy light does like Dave said except you can be a lot further away. Also, it kinda acts like a detector where you don't have to even make contact with the wire you're looking for.
The nice thing about this type is it can lead you to a break in a wire.

The passive probe works like a continuity or can listen specifically for Ethernet type traffic.

To do complex tracing you connect the active injector box on one end and listen with the probe.

It's what they use in IT but also radio, telecomm and cable TV. There can be chance for a gotcha because it's possible for adjacent wires to couple in harness like in our trucks because the wiring isn't expected to be immune to common mode noise. It's the same reason why ham radio noise can be a problem to/from you ECU or alternator.
Good to know. I saw something similar on the combination meter schematic where it listed a blank and in actuality, there was a wire there. Don't they have proof readers in Japan? For someone who can barely spell ECU, this type of typo doesn't help.
You know, I'm not sure how that works. The manuals themselves are actually published by a 3rd party. Toyota FSMs, at least in the U.S., are published by a company called Helm. They do manuals for many of the auto companies but do a lot of other marketing and distribution things.
What I don't know is who is responsible for the actual content, edits and corrections. I assume the factory provides technical info but maybe Helm generates the nice looking art work and text. But not actually being engineers or mechanics they probably don't know errors to that detail so if no one from Toyota tells them to fix it they won't.
 
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Stuckinthe80s

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stusic

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It's hard to tell from the pictures you showed, but it may be showing two different wiring configurations based on different options available?
 

Stuckinthe80s

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In my quest to learn what a "Circuit Opening Relay" actually does, I found this video that shows a guy using a wire tracker. It is at the 5:30-ish mark.

And for the more automotive electronics savvy, I realize circuit opening relay sounds self explanatory but I still wanted to confirm.

For those who aren't so savvy, the guy explains it in the video. Essentially it only sends power to the fuel pump if the key is on and/or the engine is running, so basically a safety cutoff.
 
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