U0073 Chevy Silverado | Cause and Solution

The engine code U0073 is one of the network disturbance problems with your vehicle.

The engine warning light shows up when there is a problem with the communication system.

It is known as the “no communication issue.”

It is not advisable to drive with this code.

So you must diagnose the root cause with an OBD-II scanner and solve the issue before driving your truck.

In this article, I have discussed the causes of U0073 and how to diagnose and solve the issue.

To learn about other OBD-II trouble codes related to the Chevy Silverado and Duramax engines, check out the following articles:

What Does Code U0073 Mean?

The U0073 code means an issue with wiring or software.

This code also refers to Control Module Communication Bus ‘A’ Off.

It is concerned with the communication circuit.

When the control module cannot communicate properly, the U0073 code is detected in the OBD-II scanner.

There can be a problem with the data network, damaged wiring, or the entire connection.

The engine warning light pops up when the problem arises.

Symptoms of U0073

Depending on the engine type and model year of the Chevy Silverado, the symptoms of the U0073 code differ.

The most common symptoms are:

  1. Check engine light illumination.
  2. Lack of power.
  3. Poor fuel economy.
  4. Instrument cluster gauges come on all the time.
  5. Hard to start the engine.

Code U0073 Chevy Silverado [3 Causes and Solutions]

The U0073 Code in your Chevrolet Silverado indicates the interruption of communication between your vehicle’s control modules.

I have talked about the cause and solution of the U0073 code below.

1. Short Circuit

The U0073 code can be triggered by an open or short circuit on the CAN bus.

When the wires get torn apart or separated from each other, it hampers the circuit.

Because of the short circuit, the U0073 code appears on the scanner.


Once you identify the cause, you should fix it as soon as possible.

To fix the problem, it is wise to replace the wires.

2. Lost connection

Short to ground on the CAN bus A circuit can cause the communication problem.

Lack of communication means the ECM (Electronic Control Module) doesn’t get any information, and the engine warning light turns on.


A network problem is one of the most significant issues while driving the truck.

It is, therefore, essential to seek expert assistance to fix the communication problem.

3. Faulty Control Module

Another possibility is a malfunctioning control module.

It disturbs the entire control panel.

As a result, the sensors cannot communicate with the ECM.


There is no other way than to replace the faulty control module.

How to Diagnose Code U0073

How to Diagnose Code U0073

If the U0073 code is not found and fixed quickly, it can cause a big problem.

Therefore, you should diagnose to find out the root cause and solve the issue before it becomes serious.

Follow these 6 steps to diagnose properly.

Step 01: Check Other Codes

It is possible to show code U0073 for other control module-related issues.

To fix the U0073 code, you must ensure no other codes are on the scanner.

If there are any, clearing those codes will automatically remove the U0073 code.

Step 02: Check Visually

Ensure the passenger-side ground wires connected to the PCM are not corroded.

Make sure your wires are not frayed, broken, melting, chafed, or bare.

Step 03: Check the TSB Module

Check your TSB (Technical Service Bulletin) control module.

Get your TSB checked by an expert auto mechanic if you don’t have past experience.

Step 04: Check Network Resistance

Verify your network by measuring the resistance between VLC pins 6 and 14.

If they have 60 ohms, the network wires are not open or short.

In the case of damaged wiring, you need to repair the harness.

After checking the harness, you should also inspect the harness connection.

You may need to use an electrical contact cleaner to clean the pins.

Step 05: Check the Fuse

Check the fuses, like fuse 56, the ECM (Electronic Control Module) battery fuse, and the engine fuse, to figure out what’s wrong.

The problem occurs when any one of the fuses is not working properly, especially the engine fuse.

If the engine fuse is not hot even after starting the vehicle, it means there is a problem with the control module.

Step 06: Check the ABS

Make sure you check your ABS (Anti-lock Braking System).

By using the OBD-II scanner, you can check your ABS to find out if there is any problem.

Final Words

Now you know the possible cause and solution to code U0073 on your Silverado truck.

First, diagnose and find out which factor is triggering the code.

Then, you can easily remove the code and drive your truck safely.

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