Code U0073: Control Module 'A' Communication Bus Off [Fix] (2023)

Is your car not getting enough power to start or drive? The problem here could be a U0073 code.

The U0073 code means that there is a problem with the "A" communication bus. This bus is responsible for transferring the control module signals between different parts of the vehicle. So when this bus is not working properly it can lead to all kinds of problems.

Code U0073: Control Module 'A' Communication Bus Off [Fix] (1)

In this blog post, we will discuss what the U0073 code is and how to fix it. We'll also discuss some tips to help you avoid this issue in the future. So if you're curious to find out more, keep reading!

Index Show

What does the code U0073 mean?

If you get error code U0073 when trying to start your car, there is a problem with the vehicle control module's “A” communication bus. Ocan transport It is responsible for transmitting the signal between the various control units of the vehicle.

Therefore, if it is not working correctly, the different systems in the car will not be able to communicate with each other. It can cause problems, from the engine not starting to the dashboard not showing any information.

(Video) U0073 control modul লস কানেকশন ,Toyota RAV4

Symptoms of the U0073 Code

The malfunction indicator light (MIL) is on

ANDMalfunction Indicator Lamp (MIL)in your car notifies you of any faults that may occur. If the MIL is lit, it could mean that there is a U0073 code stored in the vehicle's computer. This code is forPowertrain Control Module (PCM)and it's usually because of thatnon motor problemthe transfer.

lack of power

If you try onelack of powerOn your vehicle, this could be a U0073 code character. This code represents a loss of power steering and can usually be caused by a faulty power steering pump or low fluid level.

bad fuel consumption

Poor fuel economy can also trigger the U0073 code. There can be a variety of factors that contribute to this. In some cases, it can be caused by something as simple as a dirty air filter or adefectiveoxygen sensor. However, it could also indicate a more serious issue with the vehicle.

All instrument panel indicator lights are on

Several indicators inThe instrument panel may light upwhen a code is stored in memory. One such code is U0073, which can be associated with many different symptoms.

Possibly no crank, no starting condition

A starting or starting condition on a vehicle can trigger the U0073 code. If there is one...fuel pump problemRelay circuit, this may cause the car not to start. A few things can cause this problem, including a bad fuel pump relay and a bad ground for the relay.

See too:P0299,P0135

O que causa o DTC U0073?

faulty control module

There are many cases where a faulty control module can causeError code U0073in a car. The control module is an important part of a car's electrical system, and if it fails, it can cause all sorts of problems.

data network problem

One of the most common causes is adata network problem. If there is an issue with the vehicle's data network, it can cause a number of issues including DTC U0073. So, if you encounter this particular code, check your vehicle's data network for issues.

Control module circuit Bad electrical connection

The U0073 code may appear on the control module due to a poor electrical connection to the affected circuit. As a result, the system may malfunction, causing the vehicle to not start or run smoothly.

(Video) CAN bus communication issues | Tech Minute

Control module harness is open or shorted

If the control module wiring harness is open or shorted, this can trigger the U0073 code, causing various problems with your car's electrical system. Symptoms may include loss of power, engine stalling orstrange electrical noises.

Is the U0073 diagnostic code serious?

The U0073 code can cause serious problems if you continue to drive with it. Indicates problems in the communication of the control unit, which can lead to serious damage due to the lack of coordination of the vehicle.

How can I diagnose and repair the U0073 code?

If you see this code, you can try to diagnose the problem.

  • First, make sure that all of yourCar systems are onand that all cables are connected correctly.
  • With everything plugged in and powered up, you should check the fuse box for blown fuses.

How do I correct the code U0073?

If the U0073 code is appearing on your car, you can try to fix the problem yourself.

  • First, make sure the battery is connected correctly. If there is a loose connection, this can cause the code to appear.
  • Also make sure the floor is clean and free of corrosion. If there is debris on the floor, it can cause problems with the electrical system and result in code U0073.
  • Finally,check the fusesand check that they are all in good condition. Blowing one of the fuses could also cause the code to appear.

See U0073 "A" Control Module Communication Bus To correct the code:

Common mistakes made when diagnosing the U0073 code

There are some common mistakes people make when diagnosing the U0073 code. Let's take a look at some of them.

  • One of the most common mistakes is not checking the basics. Make sure the battery is charged, the fuel tank is full and the oil level is correct. These simple things can often cause problems with your car's diagnostic system.
  • Another common mistake is not checking the wiring. Make sure that all connectors are connected correctly and that the wiring is not damaged.
  • Another thing to check is the car's computer for connector damage.
  • Finally, make sure thatdiagnostic scan toolconnected correctly and the software is up to date.

How do I avoid the U0073 code for your vehicle?

Here are some things you can do to avoid this code.

  • First make sure that all modules on the bus are securely connected. If one or more modules are loose, it can lead to a bus failure.
  • Second, make sure all wiring is in good condition. If one of the cables is damaged, this can also cause problems with bus communication.
  • Third, check that the control module is not overheating. If this is the case, it may cause the data bus to malfunction.

common questions

How much does an ECM cost?

An engine control unit typically costs between $200 and $800, depending on the make and model of the car. Some high-end models can cost as much as $1,500.

It's important to get a quality module that will last for years and won't cause your car's engine problems. Always check with a mechanic before purchasing to ensure you are getting the correct module for your vehicle.

How do I know if my ECM is bad?

If you are having problems with the ECM, it is important to determine if the problem is with the ECM or other components. Here are some things a bad ECM causes:
Check that the engine light comes on
– The engine does not start or does not receive enough fuel
- The engine will not start
– Engine runs erratically

What is a TCM backup?

A TCM fuse is an automotive fuse that helps protect the vehicle's Transmission Control Module (TCM). If this fuse blows, it can damage or even disable the TCM, causing problems with the vehicle's transmission. It is therefore important to regularly check the TCM fuse and replace it if it is blown.

What causes a PCM to fail?

There can be several reasons for aerror PCM, but some of the most common ones are:

- overheating
– electrical short circuit
- Water damage
- Vibration or shock damage
- software bug

(Video) Chevy Silverado No Communication

What causes the ECM to fail?

There are a variety of reasons why the ECM can fail. Some common causes are:

– Accumulation of dust and dirt
– Failure of electrical components
- moisture ingress
- media removal

(Video) Chevrolet Traverse DTC Code U0100, U0073, U0121, U0140 ECM PCM diagnosis and possible fix

final considerations

In short, the U0073 code is aDiagnosefehlercode (DTC)This means that the transmission has lost communication with the Engine Control Module (ECM). It could be due to a variety of issues includingWiring issues, poor connections, or a failing ECM.

you can take severalSteps to resolve this issue: Check connections between transmission and ECM, clean any corrosion from electrical contacts, replace a damaged electrical harness, orReplacing the ECM.

(Video) 2010 F-150...Fixing U0073 Code and shorted Cluster

If these steps don't fix the problem, your best bet is to take it to a mechanic for diagnosis and repair.

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