AutoCodes – Acura – U0029 Acura

U0029 Acura Code - F-CAN Malfunction

Quick Answer

The Controller Area Network (CAN) transmits/receives pulsing signals to/from the control modules simultaneously by using F-CAN 'A' and 'B' signal lines. Common causes include F-CAN circuit F-CAN A_H line open, F-CAN circuit F-CAN A_L line open, F-CAN circuit F-CAN A_H line short to ground. Severity is High - diagnose this code as soon as possible. Driving is not recommended if the warning light is flashing, the engine runs poorly, or safety-related symptoms are present.

What it means: U0029 Acura indicates F-CAN Malfunction.
Common causes: Common causes include F-CAN circuit F-CAN A_H line open, F-CAN circuit F-CAN A_L line open, F-CAN circuit F-CAN A_H line short to ground.
Severity: High - diagnose this code as soon as possible.
Can I drive?: Driving is not recommended if the warning light is flashing, the engine runs poorly, or safety-related symptoms are present.

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Code Popularity 12,289

How popular is this code, among other codes? Low

Repair Importance Level

Urgent (Diagnose now) (3 / 3)

Repair Difficulty Level

Advanced (Pro) (3 / 3)

What is this?

Table of contents Created and updated by William Orellana on Jul 19, 2023

Description
Possible Causes
How To Fix
Tech Notes
Cost to Diagnose
FAQs
Comments
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Code U0029 Acura Description

The Controller Area Network (CAN) transmits/receives pulsing signals to/from the control modules simultaneously by using F-CAN 'A' and 'B' signal lines. When the Powertrain Control Module (PCM) cannot send the signals via the F-CAN lines for a set time, the PCM detects a malfunction and stores a Diagnostic Trouble Code (DTC). The DTC will be set when the PCM cannot send any signals via the F-CAN A lines for at least 1 second. When a malfunction is detected, the MIL comes on and a Pending DTC, a Confirmed DTC, and the freeze data are stored in the PCM memory.

OBDII Code U0029 Acura - F-CAN Malfunction - AutoCodes.com — U0029 Acura Code - F-CAN Malfunction

What does this mean?

What are the Possible Causes of the DTC U0029 Acura?

F-CAN circuit F-CAN A_H line open
F-CAN circuit F-CAN A_L line open
F-CAN circuit F-CAN A_H line short to ground
F-CAN circuit F-CAN A_L line short to ground
Faulty Powertrain Control Module (PCM) or the Control Module that sets the code.

How to Fix the DTC U0029 Acura?

Review the 'Possible Causes' above and visually examine the corresponding wiring harness and connectors. Check for damaged components and inspect connector pins for signs of being broken, bent, pushed out, or corroded.

What does this mean?

Code Tech Notes

The MIL is cleared if the malfunction does not return in three consecutive trips in which the diagnostic runs. The MIL, the Pending DTC, the Confirmed DTC, and the freeze data can be cleared with the scan tool Clear command or by disconnecting the 12-volt battery.

What is the Cost to Diagnose the Code?

Labor: 1.0

To diagnose the U0029 Acura code, it typically requires 1.0 hour of labor. Rates vary by location, vehicle, and shop. Many shops charge between $80–$150 per hour; dealerships and metro areas may be higher, independents may be lower.

Need more information about the U0029 Acura code?

Need more information on how to fix the U0029 Acura code? Get Access to Factory Service Manuals

Need Help with the Code?

Get the U0029 Acura code diagnosed by a professional: Find a repair shop in your area

About the author: William Orellana is a Master Mechanic and Mechanical Engineer with over 30 years of experience diagnosing and repairing vehicles. Learn more about his background.

Frequently Asked Questions about U0029 Acura Code

1. What are common symptoms of the U0029 Acura OBDII code (F-CAN Malfunction)?

Symptoms may include issues with the vehicle's communication network, such as warning lights on the dashboard, loss of communication with various control modules, and potentially limited vehicle functionality.

2. What are some possible causes of the U0029 Acura code?

Potential causes include a faulty F-CAN communication line, damaged wiring or connectors, issues with control modules, or a malfunctioning CAN bus system.

3. How can I diagnose the U0029 Acura code?

Diagnosis typically involves using a professional OBDII scanner to retrieve the specific code, checking for any related codes or communication errors, and conducting a thorough inspection of the F-CAN communication system.

4. How can I repair the U0029 Acura code?

Repair methods may include repairing or replacing damaged wiring, fixing loose connectors, resetting the control modules, or replacing any faulty components related to the F-CAN system.

5. Can I drive my Acura with the U0029 code?

It is generally not recommended to drive the vehicle with the U0029 code present, as it may lead to further communication issues between critical vehicle systems.

6. How serious is the U0029 Acura code?

The U0029 code (F-CAN Malfunction) should be addressed promptly as it can affect the communication network of the vehicle, potentially leading to safety concerns and performance issues.

7. Is the U0029 Acura code easy to fix?

The complexity of fixing the U0029 code can vary depending on the specific cause. Simple issues like loose connectors may be easy to address, while more complex problems with control modules or wiring may require professional assistance.

8. Can I reset the U0029 Acura code myself?

You can attempt to clear the U0029 code with an OBDII scanner, but it is important to diagnose and address the underlying issue causing the code to prevent it from reoccurring.

9. How much does it cost to repair the U0029 Acura code?

The cost of repairing the U0029 code can vary based on the cause of the issue, the needed repairs or replacements, and whether you choose to do the repairs yourself or seek professional help.

10. How can I prevent the U0029 Acura code from coming back?

Regular maintenance checks, addressing any communication system issues promptly, and ensuring proper installation of new components can help prevent the U0029 code from reappearing.

Discuss the causes and fixes for U0029 Acura OBDII Code

Submit a New Comment

Waldem Mir
Date: April 23, 2018 at 11:25 pm

ok I was trying to find U0028 in Acura , but it seems this is similar

Reply to Comment
- Robert Anthony Coleman
  Date: April 6, 2026 at 9:51 am
  
  What is a uoo29 code in a 2009 acura tl and how to fix it
  
  Reply to Comment
  - OBDIITech
    Date: April 7, 2026 at 11:11 pm
    
    U0029 on a 2009 Acura TL is a communication network fault (F-CAN). Basically, the modules in the car aren’t talking to each other the way they should.
    
    It’s not a single “bad part” code — it means something on the network is interrupting communication.
    
    Common causes I see on these cars:
    
    • Low or unstable battery voltage
    • Weak battery or poor ground connections
    • A module on the network failing and “locking up” communication
    • Wiring issues (short, open, or corrosion in CAN lines)
    • Aftermarket electronics tied into the system (alarms, radios, remote start)
    
    First thing to check is always battery and grounds. These cars are very sensitive to voltage — even if it starts fine, low voltage can cause CAN codes.
    
    If voltage is good, the next step is to scan all modules, not just the engine. You’re looking for one module that is not communicating or reporting multiple errors — that’s often the one causing the issue.
    
    In some cases, disconnecting modules one at a time (or pulling fuses) can help isolate which one is taking down the network.
    
    If the problem started after installing aftermarket equipment, I would look there first.
    
    Bottom line: U0029 is a network issue, so the fix is finding what’s interrupting communication — most of the time it’s power/ground, wiring, or a failing module, not something simple like a sensor.
    
    Reply to Comment
OBDIITech
Date: April 24, 2018 at 12:25 am

What model and year is your Acura?

Reply to Comment
Waldem Mir
Date: April 24, 2018 at 1:03 am

I got a MDX 07 3.7
I got a vsa, SH-AWD. light on, and that's what it came up with on the scanner
Weird code.
Sometimes some folks relate the super handling with the code P0154.
Thnx though.!!
This is a wonderful site. ??????

Reply to Comment
OBDIITech
Date: April 24, 2018 at 1:18 am

Any other symptoms? according to the factory service manual. if no other symptoms are present, start by reprogramming the Powertrain Control Module (PCM). If the code comes back, the you may have to replace PCM
U0028 ACURA - F-CAN Communication Circuit Error
Read more: https://www.autocodes.com/u...

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