2013 Tacoma cranks won't start

So just to confirm this is the readings you are getting key on with the relay jumped out?

 

Yes, actually getting a fluctuating reading on the resistor, but 0 to 0.1v or less.

 

Ok what if you jump pins 3 and 4 of the fuel pump relay as well and check it there?

 

No voltage at 3-4, doesn't try to start, no sound from fuel pump. This is with jumpers still in 3-5 of C/OPN and resistor

 

So if your readings are correct it would seem there's a problem on the Black/White wire between the C/OPN Relay and the Fuel Pump Relay.

 

Ok, most obvious question is, how do I fix this? What would/should happen if I jumped 3-5 of the pump relay?

 

Your gona have to access the underside of the fuse box and find where the wire is broken/corroded.

Jumping pins 3 and 5 of the C/OPN Relay with the key on should supply power coming from the EFI Main Relay directly to the fuel pump through the Fuel Pump Relay which has Pins 3 and 4 shorted together at rest.

 

Not what I wanted to hear, but it is what it is! Ok, this has been a tremendous help, I really appreciate all the time you've spent. I hope no one else has this problem but if they do maybe this will help them as well. Thanks again, I've started watching your videos and will keep on going!

 

No problem, let us know what you find.

I'm assuming you mean the videos in my signature? They aren't my videos but those guys are really smart and know their stuff.

 

Oops, well you seem to know your stuff too! One last question, when I was looking at the schematic, the fuel pump relay has 5 wires/connectors; the C/OPN relay has 4 wires but the relays in both only have 4 prongs, is that right? Seems like the fuel relay should have 5 prongs.

 

Yes the Fuel Pump Relay should be a 5 pin relay, I was operating under the assumption the correct relay was installed.

 

It's always had one of the light blue 4 prong relays in there. Even the new relays that the shop technician put in were 4 prong. ??? I have a 5 prong Toyota relay from a salvage fusebox I didn't use, it's a tall brown one, think that will work? Looks like it's in good condition.

 

The brown one is what is supposed to be there, not sure how it worked before.

 

If that’s the case, then your fuel pump has either always been running on “High” speed or “low” speed.
Either way, you need to get the correct relay.

 

Thanks for the pics, that's exactly the one. I'll try it in the morning, let you know what happens! Gettin kinda late tonite.

 

It would only run on low speed when the PCM commands the Fuel Pump Relay on which it doesn't on startup so the pump won't run with a 4 pin relay installed as the resting state of the relay connects pins 3 and 4 together and a 4 pin relay doesn't have pin 4 populated.

 

Fingers crossed that's all it is, too bad it took us that long to get there.

 

Then how was the truck running in the first place?
Weird?

 

If that relay installed was always a 4 pin it was never correct, how it ran before I can't say for sure.
I have a theory but I'd have to do some testing to see if it's plausible or not.

 

Okay, plugged in the 5 pin connector and BOOM! She's off and running! It's idling at 2000rpm, but I've had the battery disconnected several times and for sometimes long periods of time, so maybe the ECM just has to reset itself. Weird is the name for this truck, but I'm sure those relays have both been 4 pins for a long time, probably since the original mechanic installed the new harness/junction box. Looking at your schematic and following the paths you described finally sunk in to where I realized the #4 wire in the FP relay wasn't connecting to anything. Again, I appreciate everything dm93 and TnShooter ! I was looking at having it towed back to the shop and hopefully getting the Master Tech to look at it. He's the one who installed the new fuel pump and seemed to really know about these trucks. Gotta go to work, I'll post again after I drive it and see how it does.