Need help please, won't start, no spark, no fuel

Does your scanner support other systems like ABS and SRS?
If it does and none of that will talk check resistance between pins 6 and 14 of the DLC with the battery unhooked, should be 60 ohms.

 

I tried running those and nothing (linking error) I'm using an Autel Maxicheck Pro and a Blue driver bluetooth scanner. Confirmed 60ohms on those pins just now.

 

Also confirmed with the battery connected I have 12v at pin 16

 

Check between each pin and ground with the key on and see if you have 2-3v

 

Here is what I got with the key on:

16 - 12v
15 - no pin
14 - 2.4v
13 - 10.5v
12 - 10.5v
11 - no pin
10 - no pn
9 - 0v
8 - no pin
7 - 10.5v
6 - 2.5v
5 - ground
4 - ground
3 - no pin
2 - no pin
1 - no pin

 

Seems in order, that's about all you can check there without a scope.

I guess let's go back to the engine side, unplug the MAF sensor and see if you have 5v on Pin 4 (Red/Blue) and 12v on Pin 1 (Blue/White) with the key on and relay jumped out.

Also check power at one of the injectors on Pin 1 (Black/Red) and at one of the coils on Pin 1 (Black/Red) with the key on.

 

12v at all of those with efi relay jumped and key on

 

and the 5v on maf pin 4

 

Well we've checked most of the easy stuff, just to recap the PCM won't turn on the EFI relay or communicate correct?

 

It should be if this post is correct.
That's why I am confused.


https://www.tacomaworld.com/threads...-no-spark-no-fuel.633029/page-2#post-29688284

 

Okay, I haven't responded lately because my brother in law who works for Rivian helped me troubleshoot with some help of a friend of his that was a Toyota tech. To review, here is where I am at:

The EFI and EFI no2 issue is now solved - the terminals were loose causing a poor connection. EFI no2 now has power when key is on and the CEL light is on.

There was one disconnected ground on the passenger side down by the exhaust manifold - we never found where it belonged but we grounded it and confirmed that and all other grounds were good.

We back probed all the ECM outputs and followed the pin out directions one of you posted in this thread, all were normal. I guess I should add - the truck still doesn't start, no changes

The OBDII pins were quadruple checked and we made sure all pins were making solid contact, but still unable to read with a scanner. Can bus high and low both good at the OBD2 and ECM.

The cam and crank sensor wires all show the appropriate voltages, we will try and use a scope or replace the sensors soon (its freezing, dark and raining here now... of course).

I think that's all I have, we spent a solid 5hrs going through what we could think of.

 

A cam or crank sensor problem wouldn't cause a no com.
It's starting to look like a bad PCM but I'm still curious why you can't talk to anything else if your scanner is capable of it.
I'm assuming you checked for spark and injector pulse and are missing one or both?
Even if the CAN bus was offline you should still be able to talk to the SRS, Occupant Classification ECU, TPMS, and Immobilzer modules as those are on K-line.

If you have access to a scope there's other checks we can do.

 

@WKFDRob hang in there with us man.
This is the stuff "we" like. Not many guys have the patience or access to good diag tool, like a scope.

Like DM93 said, a sensor won't cause the No Com issue. So don't just replace them "just because".
Save your money, we'll get there.


Let me do some digging. See what I can think of.

 

I might have missed it, but you did confirm the grounds were good at the ECM?

 

These grounds

 

Ill check with my brother in law, he ran those grounds. I just hooked up the scanner again and ran the ABS and SRS and the reader says:

ABS-VSC-TRC (CAN) = Pass no fault
SRS Airbag(SIL2) = Pass no fault

 

Well that is good. That means the can bus line is online and good.
It's looking like an ECM issue. Still not ready to condemn it though.
Make sure those grounds are good.

 

Alright, it's been a while waiting for shipping but I have an update and resolution to the problem. I replaced the ECM and the truck started right up!

 

Thanks for the update.

Good to hear you got it fixed.

 

Don't question it....you just bought the most reliable pickup truck with the most durable drive train of them all.