Jump to content

Recommended Posts

Posted

Hey all.  Hoping for some help!  Started my truck this morning for the first time in about a week. When I pulled out of my driveway the DIC told me to service pretty much every system in the truck (trailer brakes...no trailer attached, Stabilitrak, power steering...drive with care, 4x4, etc) and the steering wheel became ridiculously heavy with speed and tach both at 0 while moving/running.  I threw a brand new battery in it but still nothing.  The video below is AFTER the new battery was installed.   It's like the ECM isn't getting 12v or ground. The fuel gauge shows empty, which it's not, the trans isn't showing what gear it's in, and there's absolutely no cranking. All fuses are fine.

 

 

Posted

Electrical problem.

Any chance mice got to it?

Chewed wires?

 

:)

Posted

Clean and tighten battery ground at engine block.. Sounds like a low voltage concern.. clean and tighten ground wires fom battery to engine block , battery to fuse block.. don't over look any.

Sent from my SM-G965U using Tapatalk

Posted
6 minutes ago, Hillwood said:

Clean and tighten battery ground at engine block.. Sounds like a low voltage concern.. clean and tighten ground wires fom battery to engine block , battery to fuse block.. don't over look any.

Sent from my SM-G965U using Tapatalk
 

Good idea!!

Check all grounds.

:)

Posted (edited)

Hmm. That's a tough one. 

 

You could have an internal alternator fault. You might try disconnecting it, to see if that helps. 

 

To check your ground, you can take a small wire and attach it to the negative battery terminal (not the cable, but the actual terminal itself), with both cables hooked up to the battery. Then connect that small wire to the body and the engine. Then start using electrical stuff, like the starter, head lights, etc. If the small wire gets warm or hot, or the electrical components work properly, then you definitely have a ground issue. I would also grab a volt meter, and start probing stuff. If you put the negative probe on the negative battery terminal, and probe the brake light or headlights (when they are tuned on), are you getting 12+? If so, is it constant or does the voltage wander around? You might also look at any fuseable links and any main power relays. You can swap relays around to test them. 

 

Wiring is not much fun.... 

 

 

 

 

f492ab0a97de7483630f4aba5c13105b.jpg

 

 

Edited by starman8tdc
Posted

Thanks for all the quick replies!  I was just able to get my code reader to finally connect and pull codes.  The only code is U0100 which is Lost Communication With ECM/PCM "A"

Posted

U codes are communication codes... LOW VOLTAGE LOSS OF COMMUNICATION!

Sent from my SM-G965U using Tapatalk

Posted

If everything electrical looks good, I would remove the ECU and "smell it". Does it produce an odor of burnt electronics? Is it wet? Any signs of heat damage to the outer case? 

 

Also, you could clean the connections to the ECU, and maybe throw some dialectic grease at it. 

 

 

Posted (edited)

 

      I hate to say it, but you might be looking at a diagnostic shop. Running low on options. 

 

      If you go down that path, try to find one that will guarantee a diagnosis without exceeding 1 hour ($100-$150). Most won't, but some will. 

 

      Some repair shops will charge you $900 in diagnostics, and then say it needs a $1200 part. Then $2100 later, the problem is still there. Then they say: Oh, well that part needed to be replaced, but there must be another part that is bad as well. We will put our diagnostic guys back on it (after you pay this first bill). 

 

     I have seen people spend thousands on diagnostics and parts, with no remedy. 

 

     Not trying to scare you, just trying to caution you.

 

     Call 5 or 6 shops and talk to them a bit before you choose one. 

 

     If I can think of any other tests you could try, I will post it. 

 

     Good luck. 

 

 

P.S.

 

https://repairpal.com/obd-ii-code-u0100-lost-communication-with-ecm-pcm-a

 

https://www.obd-codes.com/u0100

Edited by starman8tdc
Posted

I’m pretty sure it has nothing to do with it but those gauges I saw in the video, are they newly installed? Yeah grasping at straws but as mentioned, this could get ugly.

Posted

I will guarantee you there a many more codes in the system. Need a proper scan to start with.

Posted
4 hours ago, SS502 said:

I’m pretty sure it has nothing to do with it but those gauges I saw in the video, are they newly installed? Yeah grasping at straws but as mentioned, this could get ugly.

No, factory gauges. 

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now

  • Latest Articles

  • Posts

    • Some clarification may help with some of these issues.   - Rev Industries is/was the division of BAK (now Realtruck) that makes covers under the OEM names.  So if you see one with a Ford logo on it, or if you are buying the GM Accessories cover, you are essentially buying a BAK G2 cover with different branding.   - Rev Industries now markets under RealTruck "Advantage."   - As of May 1, 2025, the Advantage covers now have a 5 year warranty.  Anything before that was a 36/36K warranty.   - Parts for the covers are available from Realtruck or BAK.  The email address to reach them is [email protected] or you can call them at 818-365-9000   - If the entire cover has to be replaced, you have to go through your local GM dealer.  Service dept opens an RO, notes the damage and submits it as a warranty claim.  Keep your paperwork handy so they can confirm when you purchased it and it's within the warranty timeframe.  Once the warranty claim is approved, Parts orders the replacement cover.  When it arrives at the dealership, service will remove and install the new one for free as labor is included under warranty.   - The Advantage covers are not the latest and greatest Gen 3 covers.  They still use the old school clamps, elevator bolts, etc...If you want the newer technology, consider buying your cover in the aftermarket world.  That way, if you have an issue you can deal directly with the manufacturer.   - Finally, RealTruck has a program with many of their authorized dealers that doubles the warranty to 10 years if the authorized dealer does the install.     Hope this helps.
    • Welcome to the group!  My '22 just crossed 150K miles.  Runs perfectly.  Oil pump belt will be done in the next 30 days or so and onward hopefully for another 150K.  Love the truck.
    • Still looks like a rivet to me in the pics, I don't see a nut and none of the pics show the head of the screw. But if you says so.....
    • Thanks for all the help so far!   I did try right from 2026 right down to 2021, and only from 2023 down lets me select the option for tire psi change, but I get the vehicle not supported error!   I'll definitely try it under Chevrolet after work today, and I'll get the sensor number from gm for my truck tire sensors. And I'll let you know if it works for me under Chevrolet!   And if that doesn't work, I'm going to guess that what @Atlas said about maybe I have a different body control module could be true!  
    • From where I'm sitting this sounds like a compatibility problem. I'm assuming the 2007 was a 900-series truck, and not an 800-series (they were sold side-by-side in dealerships that model year), since it starts and runs.   This is why I HATE post-2006 vehicles. Everything becomes a huge problem when you try to keep the thing running for longer than the manufacturer has designed it to.    I can't remember when Global-A architecture started - either '10 or '11. For your sake, you had better hope it's '11, or you're going to be spending some BIG money to correct this cluster-eff. That's something you need to find out before doing anything else. You may have several computers bricked ... but the fact that it runs tells me you MIGHT be ok here.     EDIT: Just did a quick refresher. You're screwed. This is Global-A. The 2 systems are NOT compatible in the slightest. Once you get the correct engine in there that IS compatible, you're going to need to see how many computers are locked. Absolute NIGHTMARE to straighten out, too. Your buddy might be better off cutting his losses and finding something else.   Welcome to post-2006 vehicle electronics. This is why I quit the industry, and drive nothing built after 1994. This stuff takes all the fun out of wrenching!  
  • GM-Trucks.com Clubs

  • Popular Contributors

×
×
  • Create New...