I agree with arseni, plz add one minor correction, bank 1 and sensor 2 for p0037.

Only because you said you may swap out the wiring harness, I'd go over all your connections if you fail the tests posted above by arsenii.
Especially the one under the glove box near the ECM because it will kill power to the sensor at this wire harness junction if not plugged in properly(see junction IN1 below).

See Junction IN1
(posted in fair use for commentary and discussion.)




See Junction IN1

 

Whoops, my bad, thanks for pointing it out..

 

So I dipped the precats in a sodium hydroxide solution to just clean them up a bit. I had some cat codes when the rod knock started but it was caused by the exhaust composition being out of whack due to messed up timing since they were gone when I turned the engine over the first time. The only code I had was conshaft position sensor bank one and I realized the next day that was due to the fact I forgot to plug that connector in.

bur bank 1 sensor two that isn’t even attached to the precat that’s the sensor with the bung in the y? So this makes less sense. I wouldn’t think it was an issue with the in1 junction because I used the harness that came with the car since the harness off the salvaged 05 Highlander engine was different at the ECU connections so I couldn’t use it easily.

 

Correct, junction above only is only to backtack if you replaced or swapped the harness, otherwise it is an unlikely to be an issue.

If you are getting no voltage to the sensor as mentioned above, you may have to ohm out the wires to the sensor.
It can be reached on driver side under the car.
Probing the wire will be required because the plug is located up behind the intake plenum on back side of engine in a heck of a spot however can be reached barely from below if the harness clip holding the connector up high tight to the harness was left undone.

Before that tho, I'd check connection at E4 and make sure you have all the wires hooked up there or that sensor will fail and throw a code.
(posted in fair use for discussion and commentary)

 

i have live data on my little dinky craftsman OBD scanner so I’ll check that as soon as I get a bee battery tomorrow.

is there any possibility my battery failure could be caused by the small fuel fire I had melting some of the wire coatings to the injectors and coil packs? Or would that cause a misfire before any electrical issues?
I had 2 instances where I had to check grounds and make sure they were properly connected. Could a bad ground be causing unexplained battery drain? I think the battery being dead is most likely since the alternator was checked. It’s odd considering after we charged the battery the first day we had her running the car then started 4 times with no issue. Then it started the next morning but the battery light came on in a minute then the instrument panel lights began to come on and off, the radio also went off and the windows were super slow to close and open.
Is there any chance a bad battery may explain the lack of horn? I wouldn’t think so since 7v should be more than enough for the horn. Or is it more likely to be a ground or issue with the horns or the wiring between the wheel and relay / relay and horn? I need one of those $3 lighted harbor freight circuit testers.

Correct me if I’m wrong but it sounds like you’re talking about the bank 1 camshaft position sensor connector being e4 in that diagram? I already removed the plenum and air box to mitigate that issue the other day when I replaced the power steering pump which took care of the complete lack of power steering. I feel like an idiot since I should have swapped the power steering pump for the one I was sure worked worked while the engine was on the hoist. I mostly made the bad decision and kept the one that came with the salvaged engine on there because the one that I knew worked was a noisy reman. But I will definitely be rebuilding the bad one

 

Yes if the battery was run down too low and killed a cell or two. A 10 volt reading soon after a charged up battery will surely indicate a dead cell. Another thing, a dead cell will drain the other cells kind like a short- because it puts a "load" on the good cells.

What surprises me is that it started up at all because at that point the alternator should kick in so this part is alarming and a risk of a "key on" short circuit adding more drain on the system. If I undertsand you and the car started then it shouldn't have stalled with a battery light, something is wrong.

Not likely in the area under the hood where you did the work only because most of the powered wires are behind a "key on" relay protection in the circuit somewhere so nothing under the hood shoud be getting any power with the key off that I know of except maybe a hood popped sensor or hood light or horn, etc. I havent confirmed these are powered with key off yet, just ideas.


With the keys out of the ignition you should only be drawing in the milli-amps at the battery while the ECU's "hibernate"(hood closed, doors closed, all accessories lights off) so a simple amp draw test at the battery can help answer some questions


This is the part that concerns me and looks like a "key on" short circuit maybe due to bad wiring or melted wires like you said.
The fact you started it 4 times and the battery ran down while running says bad alternator or something scary going on and could be related to the P Code you have.
If I understand what you are saying.

There are a few wires at this junction and it's easy to miss one.
Plz see junction E4 below, your P0037 Code for the sensors goes thru this path may or may not be related to your battery and horn issue, treating them as one issue at a time.






>> See E4

 

to be precise about it we started it 6 times. 4 times the first day with no issue(besides lack of horn and sunroof) then the fifth time the next morning at which is when the battery light came on and then the sixth time when triple a jumped it said the alternator is in working order but the battery was under 10v and I checked it again and saw it jumping around 6.8-7.1

should I buck up and get a multimeter? Or can I take the battery to an auto parts store and have them check it? Or if this was indeed caused by a short would that have killed the battery? And would putting in a new battery without fixing this issue be a dumb thing to do/ could the short have ruined the old battery and it will do the same to any good battery that goes in before the real problem is fixed.

also it seems evident the only damage to any wires was on some of the exposed wiring on the coil pack and fuel injector connections as well as a little on the vacuum harness with the solenoid that goes on top of the plenum. The rest of the wiring harness has pretty sturdy insulation. So should I just go ahead and splice in new wiring for the coil packs and injectors since I have an extra harness, electrical solder and a soldering pen. and it would be relatively easy for me to just cut and splice the entire harness sections that leads up to the injectors and coil packs?

how would I test the e4 junction? Disconnect at a specific connector and hold the positive mm lead on the electrical leads in the plug and the negative mm lead on the negative battery terminal?

i know a little about electricity and using a multimeter but my experience pales in comparison to your knowledgeability

also I'm pretty sure the horn gets constant power draw since you can use the horn without the key in the on position. Also I’ve been leaving the hood ajar since the hood opening wire has not been opening the hood latch without using a pair of pliers to pull it.

Also that diagram says e5-e9 is that the wrong diagram? I have a friend letting me borrow a multimeter but I think I’m going to need some more guidance. Is there a good video yu could recommend?

 

I got a little lost in the conversation, so apologies if some of the ideas already came through..

Part stores do free battery inspections, if you have any concerns, just come in and they will check it in no time. If there is a short, or Parasitic Draw in the system, and you leave the battery connected overnight, yes, it will drain the battery below a recoverable voltage, aka wreck it. To prevent it, do not let the battery discharge below about 10V, disconnecting it once you are done diagnosing, it is as simple as that.

One simple way to tell if there is an issue is by touching the terminal to the battery and watching how badly it will spark, it will spark anyway, the question is if it's bad enough. Though a proper procedure would be to connect an Ammeter in Series to the battery, below is a detailed video on hot to check if you have any draw at all, and hot to localize it.


The issues you described sound more like a dead alternator to be honest, which may be the cause of the battery's early demise as well, here is a thread on how to diagnose a no charge condition. With that, it doesn't exempt you from investing in a multimeter and a Test Light if you are planning on performing any further diagnostics.

Depending on the damage, it may be an easier procedure to perform. With that, I would strongly suggest to run crimps instead of soldering, it is a lot easier and will outlast the car if done properly, unlike soldering that makes a wire more brittle, which may cause the repair to start cracking over time, even though we are talking about years into the future. Below is a link to a crimp set with a tool.


Before testing it, you need to start with the basics, check whether you have power coming to the O2 sensor in the first place, if B2S2 has power, while B1S2 doesn't, only then start tearing into the wiring to check the splice connection. Somewhere in the area marked in the diagram above, you should see a crimped connection with 2 wires becoming one.

You will have to have a multimeter to check Continuity between the connector for the O2 sensor and that splice joint, check continuity before and after crimp, which will tell if it is just the crimp itself or part of the wire that failed. If the continuity is not present at all, there is an issue somewhere inside the wire between its respective connector and the joint. If the continuity is present before the crimp, but not after, the crimp itself is in need of a repair. If the continuity is present both before and after crimp, the issue is elsewhere, you will have to use a headlight bulb to check if the wire has any partial damage on the inside.

Yes, the horn gets constant power, it is not routed through Ignition Switch. Try checking the 10A HORN fuse, here is a fuse diagram for your car. If that is good, use a Test Light, not a multimeter to check if you have power on the pigtails.

Hope this helps and best of luck!

 

For anyone following along in the future I like to add some notes here and below.
This point above by Arseni is key, I ALWAYS unhook the battery when working on the car, leave hood up for extended periods of time, or plugging and unplugging electrical stuff.


Home Depot or Lowes sells a quality meter for anyone who needs one.
Even their cheaper meters at approx $40 are packed with features.
Milli-amp feature is needed for checking parasitic draws.
Impossible to diagnose properly without a meter but $100+ meters aren't necessary for auto diagnostics.

For anyone following along in the future...
For P0037 see post #2 above, just a review.
Resrstance comparasion between bank 1 sensor and bank 2 sensor can speed things up too(battery unhooked), like mentioned above.
Only after that is it necessary to use the diagrams I posted up as a back up plan to find harness/junction failures.

Sensor wires in the drawing above: Black/red is +12V and goes to fuse EFI No. 2(10A) and always hot when key is on, Brown wire is ground, the other two wires go to engine Ecm.

 

Ok, I got the multimeter but it’s going. To be raining all day tomorrow so I won’t get to this till Thursday.

I unplugged the battery from the terminals but if the battery is under a specific voltage will I still be able to do the specific tests necessary?

so there are 2 tests I’ve seen one where I make sure the multimeter won’t fry if the draw is too high by switching to 20 amps and then bridge the gap of the negative terminal to negative post red lead on the terminal black on the post and if there is an exissice draw above 30-50milliamps then you pull each fuse one by one to see what’s causing the draw.

then the other test I saw was to switch the meter to millivolts and use the positive and negative leads to touch the tiny exposed metal squares on both sides of the top colored plastic cap of the fuse and the one causing the draw will be above (or below?) 0.0

So am I correct in assuming either one of these tests will locate the circuit with the short if there is one?

can i / should I also test relays and the fuse box under the dash? I’m pretty sure I know where the short is I just want to confirm there is or is not one. There is also a little black box near the power steering reservoir. I was going to open it the other day but that would have required me grabbing a screw driver and I didn’t feel like doing more work than I had to. What is in that compartment? Is it more fuses?

am I going to need to get a cable tracker? Is that the best way to locate the cause of a parasitic draw without cutting the loom open? If there is a short I guess I’ll be grabbing one

 

Not really, the battery has to be charged for you to perform the tests, not to say that the battery won't be too keen on sitting drained for long, the cells start to degrade irreversibly and the battery goes bad. Look around any garage sales or local marketplaces, you can usually find a charger big enough to maintain the battery there for pretty cheap.

Both of the tests will do the trick, and both have their own benefits. To see if you even need to perform any checks to begin with, place an ammeter in Series with the battery and let it sit for about 30 minutes with all the doors closed and key out of the ignition, after which the car should be completely off and there shouldn't be any draw on the battery.

Every fuse has its own resistance, and every component that has resistance will have a respective voltage drop across it, Ohm's law states that Voltage = Resistance * Current. The resistance of the fuse is fixed, but the current that goes through it is not, so the more current flows through the resistor, the higher the voltage drop across a fuse would be, and that is exactly what is being measured in the Second method.

Both methods will likely give you a result, which one to use would depend on personal preference, at least in this case. Second method is more preferable to me, since it is easier to measure voltage than pulling any fuses, and you don't disturb the car doing so.

To check for parasitic draw, you need to inspect ALL the fuses in the car. As for relays, depends on what do you want to see there. While a relay can get stuck, they usually fail the opposite way, that is failing to latch at all. Considering how many relays are present in a car, I would say it will be a lot easier to check of you have any current draw at all before starting to tear into the electrical system, otherwise you may be up for one heck of a goose chase if there is nothing to find in the first place.

Not sure, I don't have an RX personally. Here is a fuse diagram for your car.

That's to find the open in a circuit, not a short, I don't think you will need one for this job. If two wires managed to get shorted out, it would likely be a touch to late to think about integrity of the isolation of a given wire frankly..

Hope this helps and best of luck!

 

but aren’t cable trackers are used to pinpoint the exact location of a short?

what’s an ammeter? And is there no way to use a multimeter to perform this test?

in a perfect world I would have a new battery to do this testing with but as long as there is some voltage shouldn’t I be able to pinpoint which circuit the short is located in? Let’s say the battery is putting out 5v. Doing the testing method you prefer where I touch the leads to the exposed metal squares on the fuse caps, the hood circuits should still read zero and one with a short should be putting out whatever the drain on the battery currently is? But I’m not the expert here.

also does anyone know if Toyota is good about using the same color wiring for specific circuits in their harnesses? My vehicle was made in Cambridge and the Highlander engine I got for salvage was likely made in Indiana so I’m wondering if the wiring inside the harness will have the same color wires for the same circuits if and when I need to splice in a section of the spare harness or is it going to be a total **** show trying to isolate which wires to splice in order to repair ant short? I’m bracing for the worst but hoping for the best lol.

 

Not sure, I have never used one.. From what I could gather, no they are used for Open in the circuit, though some more advanced models may be able to check for short as well. For now though, it is not a necessary component to check for draw, which may not even end up being a short, start with a simple current check and g from there.

Ammeter is a device used to measure current, it is present in most multimeters, but not all, so you will have to check if your specific multimeter has one. If not, you can pick up an analog one for pretty cheap on eBay.

The voltage drop across a fuse is already quite negligible, and as the battery voltage continues to drop, the current across the circuit, and therefore the voltage drop across a fuse drops as well, likely beyond the measurable level, not to say that this draw may be caused by some system stuck on instead a short, with the voltage that low, said system can come off on its own and stop causing the draw.

Other thing is that there is still no certainty on whether you even have a draw in the system in the first place. Before trying to solve an issue, you need to make sure that the specified issue in there at all.

Toyota tends to be a little chaotic with colors they use for the wiring, at least from my experience, so I wouldn't trust the color of the wire to make sure that I am looking at the right system. It will all depend on what damage you have in the car.

Hope this helps and best of luck!

 

I like to recommend attacking one problem at a time for simplicity and a clear path to move forward toward success.

If you like to work on electrical first I recommend doing only the minimum to make sure it is safe to start and run the car and then and only then start chasing down codes and sensors, etc.

How I would do it step by step.
Step 1: you will need a good battery or a way to charge up your old battery if it is still good and useable, no reason to go any further until this is done.
Step 2: do a quick check for shorts to make sure the car is safe to operate, see Arseni's post above for how to do it, we are only looking for big shorts that can damage the car at this step.
Step 3: get car running and verify charging system
Step 4: work on parasitic draws, codes, sensors, etc

Hint: until all parasitic draws(if any exist) are fixed, just unhook battery when not using car.
Hint: Keep it simple, one step at a time.

You've come this far and already have the bragging rights for pulling the engine without a lift, you are almost there my friend.

An ammeter is a meter that checks amps. Most multimeters have this feature.

 

im just trying to get a full picture of the process and where to go depending upon results. Preparing for contingencies wether they will or will not be a problem is just the way my brain works.

as far as I have deduced a cable tracker can perform a basic continuity test. A continuity test may not be the optimal way to find a short but it will locate the problem area within the circuit.
they have one at good old HF for $27 which is reasonable.

this is definitely less complicated than pulling the engine out and putting a replacement in but it’s still semi overwhelming.

and how would One figure out exactly which wires are the correct wires to splice? I’m guessing just hack the wire loom all the way up to the connection and use tape and a marker to identify each wire in the bad and good harness and then start stripping and splicing.

I was told solder is not the best way to go but I have the heat shrink cable covers so I would rather use solder. I really don’t like the idea of bulky butt connectors and I think if I do a good job soldering I won’t be increasing the size \ diameter of the wires by more than 10%