No crank, no start, no PCM communication

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Feb 18, 2026 | 06:41 PM

#16

Cuthbert

Thread Starter

4wd Low

Joined: Feb 2026

Posts: 10

Likes: 1

From: Texas

Quote:

Originally Posted by texastech_diesel

I'm in Ft Worth, if you were here I'd let you come grab a PCM out of my trucks but I can't get it down to you, sorry. There are a few shops that rebuild them, might be worth sending it out while you're hunting down wires.

Hey that would be nice lol but no worries. I got ahold of a mobile mechanic that might have one I can at least test on before making the commitment.

You are still greatly appreciated sir.

Feb 21, 2026 | 05:20 PM

#17

BLADE35

Hotshot

Joined: Apr 2010

Posts: 19,042

Likes: 228

From: Saratoga Springs,UT

Quote:

Originally Posted by Cuthbert

I’m getting power into the PCM as pins 86 and 30 of the PCM relay are showing 12V. But testing the voltage going out of the PCM at circuit 361 - PCM connector C1381a (left plug) at pins 34 and 46, I am only seein.

it’s got Whats it needs going to relay looks good so far

but what comes out that relay
Whats pin 85 and 87 show need to be 12 volt here

then passes thru fuse F2-22 it should be hot 12v thru fuse

At one point you mentions only 1.5v at fuse this important verify

Last edited by BLADE35; Feb 21, 2026 at 05:46 PM.

Feb 21, 2026 | 05:37 PM

#18