2019 Chevrolet Silverado Multiple U-Codes & TPMS Failures: Diagnosing a False Network Problem the Right Way
Introduction
If you’ve ever scanned a vehicle and been hit with a wall of communication codes, it can feel like the truck is falling apart electronically. That’s exactly what happened on this 2019 Chevrolet Silverado 1500—nearly 20 codes spread across multiple modules, but no check engine light and no obvious symptoms.
Situations like this are where proper automotive troubleshooting really matters. Misdiagnosing this could easily lead to unnecessary module replacements and thousands of dollars wasted. Let’s walk through how to break this down the right way and separate real problems from false alarms.
🔧 Recommended Tools for Diagnostics
When you're diagnosing modern vehicles, having the right tools makes all the difference. A basic code reader will only get you so far—you need tools that let you see what’s really going on and test components properly.
Autel MaxiSys MS906 Pro TS Professional OBD2 Scanner (with TPMS & full system diagnostics)
https://amzn.to/4mcEFlL
This is a full-system scan tool that allows access to all modules, TPMS diagnostics, and advanced functions. It’s essential when dealing with network codes and multiple systems.
Power Probe 3 (PP3CSRED) Circuit Testing Tool
https://amzn.to/4dpuXtT
This is something I use daily to verify power and ground circuits and to activate components quickly during diagnostics.
Power Probe ECT3000 Circuit Tracer (Short & Open Finder)
https://amzn.to/4cvINcf
This tool helps locate wiring issues like opens or shorts without tearing apart the harness—huge time saver.
Vehicle Overview
The vehicle is a 2019 Chevrolet Silverado 1500 with typical mileage for its age. It came in for a routine scan where multiple codes were discovered across several modules, even though no warning lights were active.
Vehicle Concern
There were no drivability symptoms reported. No warning lights. No complaints from the driver.
However, during a scan, multiple stored codes showed up, including communication faults, low voltage codes, and tire pressure sensor issues.
This is a perfect example of why diagnosing car problems isn’t just about reading codes—it’s about understanding what those codes actually mean.
Initial Inspection & Observations
Right away, one thing stood out: nearly all of the communication codes were listed as “history” and “not current.”
That’s a big clue.
When you see multiple modules reporting lost communication—but none of them are currently failing—it usually points to a single event that affected the entire network, not individual component failures.
Diagnostic Trouble Codes
The vehicle had several U-codes such as:
Lost communication with engine control module
Lost communication with transmission control module
Lost communication with body control module
Lost communication with power steering module
There were also codes indicating:
Invalid data from modules
Message counter errors
On top of that, there were low voltage codes stored in different modules.
And finally, there were active TPMS sensor codes showing low voltage and signal issues.
Step-by-Step Diagnostic Process
When approaching something like this, you have to avoid the trap of assuming each code represents a separate failure.
The first step is grouping the codes.
All the communication codes pointed to different modules, but they all shared one thing in common—they were not current. That tells you they all happened at the same time and then resolved.
Next, I looked at the low voltage codes. These are critical because voltage issues can cause modules to temporarily shut down or reboot. When that happens, other modules lose communication and log faults.
This is where a lot of technicians go wrong—they chase communication codes instead of asking what caused the communication to drop in the first place.
To confirm this, I checked the battery.
The battery tested at 778 cold cranking amps, which is solid. No issues there. That tells me the battery is currently healthy.
However, that doesn’t mean it was always that way.
A vehicle sitting for an extended period can experience voltage drop from parasitic drain or just natural discharge. During a low voltage event—especially during cranking or wake-up cycles—modules can lose communication briefly.
That explains the entire group of U-codes and invalid data codes.
At this point, the network issue is essentially explained and not an active concern.
Now, shifting focus to the TPMS codes—this is where the real problem is.
Unlike the communication codes, these were current faults. The sensors were reporting low voltage and, in one case, no signal at all.
TPMS sensors have internal batteries that typically last 5–7 years. This vehicle falls right into that window where failures start happening.
Key Findings
The communication and data-related codes were caused by a past low-voltage event, likely due to the vehicle sitting or experiencing a temporary discharge.
There are no active network issues.
The only current and repeatable faults are related to failing TPMS sensors.
Final Diagnosis & Repair Recommendation
The correct repair here is straightforward:
Replace all four TPMS sensors due to internal battery failure. Even if only two are currently failing, the others are likely close behind.
Clear all codes and verify that no communication faults return.
No further repairs are needed unless new symptoms develop.
Common Causes of This Problem
This type of situation is more common than most people realize. Some of the most common causes include:
Low battery voltage from sitting too long
Weak or aging batteries
Loose or corroded battery connections
Jump starting or improper boosting
Module sleep/wake communication glitches
For TPMS issues specifically, internal battery failure is the leading cause.
Lessons for DIYers & Used Car Buyers
This is a perfect example of why automotive troubleshooting requires context, not just code reading.
If you saw 15–20 codes on a scan tool, it would be easy to assume the worst. But understanding how modules communicate—and how they react to voltage changes—completely changes the diagnosis.
For someone doing a used car inspection, this is exactly the kind of thing that can be misinterpreted.
A seller might clear codes before you see the vehicle. Or you might scan it and panic when you see a long list of stored faults.
The key is knowing which ones matter.
Always check if codes are current or history. Always look for patterns. And always verify battery condition before going down a diagnostic rabbit hole.
Don’t Get Burned on Your Next Used Car
If you’re thinking about buying a used car—or even if you already have one—this is exactly the kind of problem that can slip through the cracks and cost you big money later.
After 35+ years in the automotive field, I’ve seen firsthand how often people end up with vehicles that have hidden issues just like this.
That’s why I put together a simple Used Car Guide to help you understand what to look for and how to avoid making a costly mistake.
It’s a quick, practical guide designed to give you the right mindset and approach before you buy.
👉 Get the guide here:
https://stan.store/BobbyWhiteside
It’s a smart first step toward making a better used car decision.
Disclaimer: Some of the links in this post may be affiliate links, which means I may earn a small commission if you purchase through them—at no additional cost to you. I only recommend tools and products that I personally use or trust in real-world diagnostics.
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