No Crank, No Click, No start, no electronics

Just picked up this 2015 taco over the weekend. The previous owner left it sitting for a bit and the battery was fully drained, I hooked it up to my 4runner to try to get some life back into it and was able to hear a clicking noise but wouldn’t crank. (All electronics in the car worked at this time) I figured the battery was just old but I let my dad try to help me jump it later that day and he accidentally reversed polarity on the terminals and the horn keep blowing before we were able get the cables off. I noticed after the fact that he blew the 140a fuse, etcs fuse, and radio fuse. (Visually all the fuses in the engine bay and inside of the car are fine but I didn’t test them or the relays with a multimeter yet) after putting a new battery in none of the electronics in the car works (windows, radio, locks) and the dash is lit up like a Christmas tree

Any idea on what I should tackle first? Ideally it should just be that pain in the ass fuse and hopefully didn’t fry the ECU but I have no idea

 

Check the 7.5A ECU-B fuse.

We have a lot to check. But check that one first.

 

Also, did you check the fuses in the cab?
They are behind the little cubby door on the left side of the steering wheel.

 

Geez, you may need to check that there is power going to each fuse circuit as well.

I have a thread on how to access that alt fuse. You’ll get a good view of the fuse circuits from below.
https://www.tacomaworld.com/threads...-box-battery-wire-replacement-upgrade.420450/

 

FWIW, I don't think you fried the ECU.
Your check engine light is on. The ECU is what turns it on.
I'm betting it's a power failure at a fuse.

 

A reverse jump start is never a good thing but let's address the no crank first since there's no modules involved there, verify the AM1, AM2, and STA fuses are good first.

If they are then follow the steps outlinged in the post below and see what you are missing.
https://www.tacomaworld.com/threads/2nd-gen-information-diagnostics.784008/#post-28042155

 

Your ign switch has two independent poles each fed by its own FUSE. i would begin there.

it is more likely the one circled in blue is open (blown, bad, kaput, tits up) and therefore you are probably losing any output from the ign switch to IG2 and ST2 outputs or you have a bad IGN Switch.

(IG2 doesnt show the wire attached on this page but on a different page which i havent included, it directly powers your coils for spark plugs) (and on a even different page it also powers your fuel injectors)

but basically if your lighting up the dash then IGN1 likely has power because your ecu is powered

if your starter isnt engaged then the IG2 and ST2 arent passing power to engage starter and to power the coils and the injectors

due to maybe the fuse circled in blue being blown

You didnt say, but im assuming this truck is a 4.0L maybe the offroad version that has the 130a alternator because you are saying you have the 140A fuse?

you also didnt say why the truck was parked, did you ask the seller if it worked before they parked it for so long, not that you can trust the answer unless you know them.

was it failed and then it sat and they didnt tell you this?

i doubt it was operational when they parked and stored it. maybe a wire at the ign switch broke. if you cant find a fuse bad then maybe thats why they just left it sitting and then sold it . so you may have to access the ignition switch, unplug it and put the key in and move it to each position and ring out the wiring to check its not internally broken

 

like i said IG2 just goes to the coil packs and it says outputting even when the key is moved to start to momentary add in the ST2 output shown on my previous post, the click you hear is likely the STA relay pulling down trying to pass the ST2 to the starter solenoid, your probably not hearing the start solenoid clunk. remember, looking at the previous post, the STA relay gets powered by IG1 and so does the ECU so thats the click you hear and why the dash is lit up and a good indication IG1 and ST1 outputs are fine and AM1 fuse is good.

ill just page one page, the other just shows the power from IG2 going to the remaining 3 of 6 coil packs oh and on a third drawing for Engine control (not pasted, but trust me, the IG2 also goes to the 6 electronic injectors to power them open when the fuel duty pulse triggers them.

even if you could jump the starter, the engine wouldnt crank because no ignition coils and no injectors are powered if AM2 fuse is blown or that ignition switch is bad or any wire bewteen or coming out of the IGN SWITCH Number 2 poles

can i also assume this is a Automatic transmission vehicle? again you didnt say

if so you could, go put the key in turn to run, step on brake and take it out of park. put it in reverse.. and then turn the key to START and you wont hear the STA relay anymore. so thats a way of also confirming what that click you hear is coming from. youll hear in when trying to start in park, and not hear it when trying to start in rev. that will confirm and rule out a few things:
AM1 is good, IG1 output is good, your gear selector switch is good and the STA relay is good and pwoer getting to all those things, which if you try that, then for sure we can rule out AM1, IG1 and ST1 and then focus on the AM2 fuse and all down stream paths of it.

these are thngs that can help you save trying to ring things out with a meter, secondary indications to determine what is getting power and what isnt. based on your responses i can provide more because i design and certify aircraft avionics and am an engineering test pilot for 42 years of my life and can help you read a print and save you time by giving you tests to try and what you look for.

 

I circled the fuses in the engine bay that were visually blown. The ones inside the cab were visually fine but I haven’t gotten around to testing them for continuity yet

 

The truck is a 4.0 auto but I checked online with Toyota to verify that it’s a SR5 with tow package

the previous owners are customers at my restaurant and the car was salvaged due to mold on one of the seats. Not a ton of water in the car but enough for them to cash out on insurance. They were able to drive it fine for at least a month before it sat with the adjusters for a few weeks. They were able to drive the car back up to my work as well where it sat for another week or two before all of this happened

 

I will try that once I sort out the blown fuses. Right now when I put the key in the ignition I’m just seeing all the lights pop up and I can’t change gears unless I use the safety release. Prior to my pops reversing polarity everything in the car was working (Windows, radio, locks, etc.) but now I can only really use the hazard lights

 

Do the brake lights work?
That's an easy test. And will get us started.

 

It was supposed to rain today so my buddy let me push it into his detail shop for the next couple of weeks while I sort all of this stuff out & I honestly didn’t even check before we put it away

 

We can surely figure this out.
The water issue is more a concern to me, than the reverse polarity jump start.

 

Yeah so the original owners were able to drive the car for quite some time, they didn’t even list it for sale they kind of just brought up how they had to “salvage” the car (they all know that I have a thing for 4Runners and tacos) and I asked what the insurance buy out was. I ended up paying around $5k for the thing since I felt like I could somewhat easily part it out to make the money back or get it back on the road for fairly cheap but then it sat for a bit and then this all happened

again, the car was driving fine before it sat for awhile dealing with insurance

 

Water damage always shows up weeks to months later.
That's why no one wants to deal with them. You can't guarantee your work.
The only way to do it right is disconnect all the plugs and components and dry them out. Then use electronics cleaner on the contacts and "hope" that was good enough.

Either way, I feel like you can get it back up and running.

 

I started ripping out the interior the other day as well since the smell was giving me headaches. Once it’s fully stripped out and out of the truck I’ll start checking for corrosion/leftover water. As of right not I have all the seats out but haven’t worked on the center console or the carpet

 

So far everything in the car seems dry, they had fans running in the car for a few days after the water had got in

 

Shift lock solenoid not working? yeah like TnShooter says, lets start back to basics with "do the brake lights work?"

sounds like your 140a fuse hasnt been changed yet because that alternator fuse connects what i call the battery direct buss to the alternator direct buss even when the alternator isnt running. your basic essential systems for brakes etc are there and if you have no brake lights and you have no shift lock solenoid, you've got no power on that buss and it should always be hot when the battery is working and/or if the battery fails and the alternator is working. if the alternator fuse is good regardless with no key on and engine running or not. brake lights have to work.... regardless for safety hence why on that buss. imagine worse case scenario, you are driving at speed at night downhill towing with a trailer brake control system sending power to the trailer brakes when you step on your brake pedal. Imagine engine dies, everything dies, you want people behind you to see your brake lights working as you are r trying to get it stopped and over to the side of road and you need those trailer brakes to keep working. or say your battery gives out but your engine and alternator are still running, or your truck just drew too much power, the 140a would blow to protect the alternator and keep it feeding your trailer brake system and tail lights.

so like TnShooter says.... check if your brake lights work.... dont even put a key in the ignition, just step on the brake pedal and see if they come on.



there are plenty of very good people on here that are willing to help you if you provide solid feedback to them or me. ill check back later.

that shift lock also works by the 10A STOP breaker that is the same one that feeds your stop lamps on your tail lights.

he is asking you not because of that fuse, but to see if the (BAT) buss is hot so we can determine if your alternator fuse is restored working and that buss is alive or not

 

Basically what TnShooter is trying to have you check is this:

the red is what i call the ALTERNATOR DIRECT BUSS

the green is the BATTERY DIRECT BUSS

the BLUE is the Alternator fuse that joins them

so when the alternator is not running, the batt direct buss can still feed the alternator direct buss via the fuse.

so he is trying to see if the red buss bar line has power on it from the battery by having you step on the brake and see if your tail lights come on.

as you can see he just picked the brake system as a quick way to see if the buss has power because the brake light system is the fuse shown circled in yellow which is one of many things powered by the alternator direct buss and if that ALT 140a fuse is blown the entire red buss bar is dead and cant get power

regardless of key and when engine is not running that red buss bar should be hot and alive from the green battery buss always via the 140 amp fuse..