SOLVED! U1000 U1016 no start no crank

[User#3]

I have 2006 buick rainier 4.2 with a no start no crank condition. After checking the starter relay everything seems good. The pcm is not grounding the starter relay circuit. Swapped pcm and same issue.

I have no communications to the pcm with tech 2. I also have no radio, hvac lights. Looking at wiring diagrams and possible fixes for the last couple of weeks has me puzzled. Everything seems to check out but i know i must be missing something stupid. Gounds on pcm connectors seem ok.

Can anyone provide some diagnostic info on where to look next. I've looked into both splice packs and have signals on most modules. I believe it pcm wiring related but i cant seem to find a trouble tree way of diagnosis for the U1016 code. Im usually pretty good with electrical diagnosis but dont have experience with class 2 communication, still learning.

Im going to check pcm c1 pin 13, 18, 19, and 20 for power after work. Any help is greatly appreciated since ive been researching way too much and am getting blinded by possible causes.

 

[mrrsm]

Welcome to GMT Nation...

This entire Thread will assist you...BUT... Bounce to Post #33 FIRST...and Download, Save and Use... the information provided by Will Robinson's Epic Class 2 Video Example Seminar.

You have the Tech 2 so you are MORE than Half Way There to a Solution...You might also try getting an inexpensive Two Channel Oscilloscope for the OTHER Half... but you "WILL" (Pun Intended) be able to sort this issue out in a very direct manner even without one.

SOLVED! - No Start, Multiple U1000 codes, Class 2 Serial Communication Problem

2005 Chevy Trailblazer LT, 2-Door, 4WD, I6 4.2L engine Won't start or turn over. No starter signal at starter relay but when jump relay will turn over but not start. No check engine light. All instrument light on when first to key on the go out except battery & gauge warning light stay on...

gmtnation.com

Beware HANTA Virus Carrying Mice and Rats setting up "Homes on Homes Under the Hood"

( The Under-Hood GMT360 Images come to us courtesy @christo829 )



Use a Bright Flashlight, Eye Protection, an N-95 Mouth and Nose Mask and M11 Nitrile Gloves...Clean Up the Friable Feces and Urine with WET WIPES Only... NO COMPRESSED AIR or Canned Air. Keep the Infected Dust and Nesting Materials quiescent... Carefully Dispose of the Rats-Mice in Traps and other Debris in Large Zip Lok Bags...Keep Family, Strangers and Pets AWAY while you work during any Clean Ups:

Clinical Overview of Hantavirus

Hantavirus infection causes potentially serious diseases. Hantavirus is spread by rodents.

www.cdc.gov

Much More about Oscilloscopes HERE:

How To Use PICO #2204A & HANTEK #1008C Oscilloscopes

You don't need a Huge Bag of Coins in order to obtain and use an Oscilloscope for performing In-Depth Wave Form Analysis in Automotive Applications on everything from Problematic Electronic Fuel Injection to obtaining accurate Compression Tests to Diagnose Internal Engine Conditions. HANTEK...

gmtnation.com

Hope These All Help... :>)

 

[User#3]

Thank you

 

[TJBaker57]

I've looked into both splice packs and have signals on most modules

Can you elaborate on this? You "looked into" them with what? And what do you you mean you have "signals" on most modules?

If you happen to have one of these $15 bluetooth OBD adapters it is possible to simply look at the data stream for clues.

https://www.amazon.com/dp/B011NSX27A/?tag=gmtnation-20

Here is a sample look where I just monitor the data stream.

 

[User#3]

Thank you for all your help. I found a very small cut in the orange 12v battery wire pcm 20 to fuse 10, near the harness. Started it up and i plan on patching all the wiring up tomorrow. I tend to overlook the simple things but im glad it was an easy fix.

 

[mrrsm]

...and as the OP Solves the Problem in the End... The Crowd Goes WILD!

What an AWE-Spicious (Auspicious) First Thread!


You've just Won a FREE Tech2PATHS PDF to assist You with a WIDE Range of GM-GMC Class 2 Network, System and Module via Tech 2 Diagnostics: