Truck cranks but will not start [Solved].

Correct, the APP sensor disconnected and it has the same values

 

Does the APP use the same IF1 connector?
I don’t even see that sensor on my diagrams.
I see one that is on the throttle body?
If the APP goes through the IF1, wouldn’t unplugging the IF1 work?

 

I'm about to go over to my truck and do a couple experiments but if your powers and grounds are good but we have no 5v ref with everything unplugged it's looking like a failed PCM.

No the wires go straight to the PCM, the VCP2 and VCPA wires are the 5v ref wires.

 

I'll start looking for a replacement. I have a code reading coming in. Will that help identify the PCM problem?

 

Well based on what I just learned on mine we need to revisit the EFI main relay circuits.

 

I'm all ears. What should I check?

 

So, killing the 2 power feeds from the EFI relay will kill the 5v reference?

 

I was under the impression that the PCM wouldn't turn on the main relay if the 5v ref was shorted but it appears the 5v ref doesn't turn on unless the main relay is on, this is different behavior than I'm used to dealing with.

 

Based on what I just learned by pulling the EFI relay, no CEL, no com, no 5v reference.

 

I took a guess, guess I might have been right?
https://www.tacomaworld.com/threads/truck-cranks-but-will-not-start.799571/page-3#post-28663843

 

Leme go get a pinout for the relay and I'll update in a few.

 

#13

 

Key ON
12v to pins #5 & 1
Ground at all times on #2

 

Ok at the EFI relay, key on.
Pins 1 and 5 should have power and pins 2 and 3 should be ground.

Test light to battery negative and pin 1


Test light to battery positive and pin 2


Test light to battery positive and pin 3


Test light to battery negative and pin 5

 

OP, be sure to carefully read above DM93 pictures.
Make sure your leads are on the correct battery terminal. 2 of the test are from the opposite terminal.
Let us know what you find.

 

1 and 5 have power
2 and 3 have ground.

That all checks out good

 

Swap the relay with the horn relay, plug everything in, and see what happens.

 

Check engine light is now on. It's cranks but still doesn't start

 

Ok finally some progress, so the EFI relay was bad. I bet your horn doesn't work now.

Do you have 5v at the PC E4 Pin 23 (Blue) now?

 

Nice, finally we have progress.
Make sure everything is plugged in also.
We’ve had quite a few connections unplugged.
It’s easy to forget to plug one back in.