Newish member and I come with a puzzle

I have a 2007 Toyota Tacoma. At first, it was great. One day my son drove it, then he came inside and said, "Hey, your truck is cranking but not starting." I went outside, took a look; the only thing that I noticed was the battery terminals looked dirty-ish but not bad. I had just put a new battery in 9 months ago, so I pulled the battery terminals off, gave them a scrub, and the truck fired right up and ran perfect, no codes. So I thought, "Okay, poor connection." I drove it every day for the next 2 weeks, no problems. My son drove it around, then came back in and said, "Hey, your truck is cranking but not starting again." So, of course, I’m like, "WTF are you doing to it?" He said, "Nothing, just driving." So I go and look, check relays and fuses; don’t really see anything, but it fires right up, drives normal. Another 2-ish weeks later, I get off work and it cranks and no starts on me. So I mess with it, looking stuff over; everything looks good. I blew some cold air in/on the ignition, nothing. I disconnected the battery for an hour, nothing. I had my son bring up spare keys, nothing worked. I left it there overnight, and the following morning I tried again; it fired right up and ran perfect. So I figured I’d drive it home after work, but nope, got off work, would not start. I left a key with my son and he tried when he got off work and it started right up, so he drove it home. I worked on it at home, got nowhere; my wife ended up getting it to start. So I pulled the positive terminal off; it stayed running. Then I disconnected the MAF; it immediately freaked out and threw a code. I plugged it back in, went right back to running normal, and the code went away. I kept looking it over, and after about 30-ish minutes it shook and died, and I had just about a full tank. So I put a new fuel pump relay in and that didn’t work. I also swapped the open circuit relay with the horn; that also didn’t work. I knew I wasn't out of gas; it would not restart. The next morning it started, so I checked fuel pressure; it was around 60 psi. It died. I checked again, 0 with key on and at crank, so I also couldn’t hear the pump. So I dropped the tank, replaced the fuel pump, got it back together, and it read no gas with the gas light on. So I dropped the tank again, tested the wiring harness; it was good. I pulled the pump, fixed it, made sure it was in the right spot, got it all back together, still read no gas and still crank no start. So I bought a bidirectional scanner, plugged it in, and told the fuel pump to turn on, and it did, and the truck started right up. The next day, still a crank no start situation. So I talked to some people; they suggested I put the OEM pump back in and that I replace the crankshaft sensor. So I went ahead and replaced the crankshaft sensor, and what a mofo that was. Still didn’t start. I’ve also replaced the camshaft sensor; still no start, solid crank though. I plugged the scanner back in and it wouldn’t connect. So I went through the whole truck testing harnesses everywhere, pulled every ground and checked wires, sanded them and connectors, and put the grounds back. Nothing. I unplugged the battery and gave up. A friend's dad stopped by to take a look and, of course, it fired right up. He also suggested I put the OEM pump back in as he didn’t think it was the pump. So the next day I put the OEM pump back and nothing. So I pulled the ECM out, put it in the freezer for like 30, put it back and nothing. The next day it started and gave me a check engine light. The scanner finally connected and I got a B1801 and a P0543, as well as my AC light started to blink. I was going to try and drive around the block, but as I was about to do that, the truck died. Then the AC light stopped blinking and blowing cold air, and the check engine light went away, and as usual, crank no start. I'm sorry, I know that was a book and probably a headache to read, but I don’t know what else to do. I was determined not to let the truck beat me, but your boy is tired and I'm at a complete loss.

 

Welcome to TW..

 

It’s kind of hard to understand due to lack of punctuation but is it not starting with one key and starting ok with the other?

 

When it cranks but no starts it won’t start with any key I have 3

 

Paging @Dm93

 

My eyes are sore trying to read that

Have you checked Connector IB1 Pin 8 (Black/Red) behind the left kick panel? That's a relatively common issue for it to get burnt.

 

Is it the one my figure is on

 

No it's the white one that's vertical below it.

 

Welcome aboard!

 

Paragraphs please...welcome

 

If this is correct looks good to me

 

I think the son is the issue? That’s typically the problems I have.

 

That may be the longest sentence I've ever seen...

My sister had a Gremlin with the same problem. Kind of appropriate for a Gremlin, eh? We tightened all the grounds and electrical connections, replaced the alternator and the battery, and still had the problem... but the problem disappeared at some point and we have no idea what happened as we'd never done anything to fix it after the last episode. Just went out, cranked it up, and drove forever...

 

Bro...

 

Plus 1, maybe if your lucky @TnShooter will try to decipher that too OP

 

I know its bad I’m super stressed and at this point feels like my brain is shutting down

 

EDIT:
Didnt realize you already replaced the fuel pump....
Have you checked for spark when its acting up?

Also at this point you have nothing to lose, throw an oem replaceent crank sensor connector at it....
Maybe its a wire fitment issue, not making a good connection at times...
Did inside the connection look dry & zero contaminants, water, oil, etc...

 

What we know,
Symptom: Crank, No Start

Diagnosis tried:
1. Tried Different Key - No change
2. Clean battery Terminals - No change
3. Swapped Fuel Pump and C/Open Relay - No change
4. Disconnected battery - No change
5. New Fuel pump - No change
6. New Crank Sensor - No Change
7. New Cam Sensor - No change


*********After all these parts replaced. Now we have a no comm with ECM.*******
And codes B1801 & P0543 and a blinking AC light.
I have NOT read the rest of the thread yet.
Just deciphered for those that want to follow along. (Easy reading)

 

Ok, FWIW.
I skimmed over the thread.

What I didn't see (or missed)

1. Have we confirmed the Security Light is NOT flashing when this happens? (I don't care if we tried new keys. Means nothing. The light is the indicator)

2. Does the Tach move when cranking? (You said you can command the Fuel pump ON, and then the truck will run) - (Also, you said, 0 psi of fuel on cranking)

3. *****Also, are you sure the code was a P0543? - ***** My FSM shows no such code for the 2007 Tacoma.

4. You have an OPEN circuit for the Driver Side airbag. - (Doubt they are related, but worth seeing if starting is shared on any common connectors)

5. I'd like to know what the voltage is to the IB1 pin #8 (Black/Red wire) when this happens. (See DM93 post above for Where it is)

 

When i get in truck the security light blinks once key and or keys have gone in it goes away

tach dosnt move

ill check volts on ib1 when i get back to the house