AutoCodes – Pontiac – U2104 Pontiac

U2104 Pontiac Code - Controller Area Network Bus Reset Counter Overrun

Quick Answer

Modules connected to the Controller Area Network (CAN) serial data circuits monitor for serial data communications during normal vehicle operation. Common causes include Faulty Control Module, Control Module harness is open or shorted, Control Module circuit poor electrical connection. 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: U2104 Pontiac indicates Controller Area Network Bus Reset Counter Overrun.
Common causes: Common causes include Faulty Control Module, Control Module harness is open or shorted, Control Module circuit poor electrical connection.
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.

Save to My Repairs My Repairs

AI answers can be wrong. Verify repairs with testing. Open full chat

Code Popularity 853

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 Feb 04, 2021

Description
Possible Causes
How To Fix
Cost to Diagnose
FAQs
Comments
Add Comment

💬 Need more help? Ask Coddy for instant answers — it's free!

Code U2104 Pontiac Description

Modules connected to the Controller Area Network (CAN) serial data circuits monitor for serial data communications during normal vehicle operation. Operating information and commands are exchanged among the modules. If no communication is detected on CAN serial data circuit, the Diagnostic Trouble Code (DTC) is set. A total non-communication condition may be caused by a short to battery or voltage on any of the CAN circuits or a short between the CAN high and low circuits.
The following modules communicate on CAN serial data bus: The Body Control Module (BCM), The Electronic Brake Control Module (EBCM), The Engine/Powertrain Control Module (ECM/PCM), and The Transmission Control Module (TCM).

OBDII Code U2104 Pontiac - Controller Area Network Bus Reset Counter Overrun - AutoCodes.com — U2104 Pontiac Code - Controller Area Network Bus Reset Counter Overrun

What does this mean?

What are the Possible Causes of the DTC U2104 Pontiac?

Faulty Control Module
Control Module harness is open or shorted
Control Module circuit poor electrical connection

How to Fix the DTC U2104 Pontiac?

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 is the Cost to Diagnose the Code?

Labor: 1.0

To diagnose the U2104 Pontiac 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 U2104 Pontiac code?

Need more information on how to fix the U2104 Pontiac code? Get Access to Factory Service Manuals

Need Help with the Code?

Get the U2104 Pontiac 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 U2104 Pontiac Code

1. What are the common symptoms of OBDII code U2104 on a Pontiac?

The common symptoms of code U2104 on a Pontiac may include the check engine light illuminating, issues with vehicle communication systems, and potential difficulty starting the vehicle.

2. What does the OBDII code U2104 on a Pontiac indicate?

Code U2104 indicates a Controller Area Network (CAN) Bus Reset Counter Overrun error, suggesting a problem with the communication network in the vehicle.

3. What are the possible causes of OBDII code U2104 on a Pontiac?

Possible causes of code U2104 on a Pontiac include wiring or connection issues in the CAN bus system, a faulty CAN bus module, software glitches, or a malfunctioning control module.

4. How can I diagnose the OBDII code U2104 on my Pontiac?

Diagnosing code U2104 may involve using an OBDII scanner to retrieve the code, checking the CAN bus connections and wiring for any damage, and testing the control modules for proper functioning.

5. Can I still drive my Pontiac with OBDII code U2104?

It is not recommended to drive your Pontiac with an active U2104 code, as it can lead to communication issues within the vehicle and potentially affect its performance and safety.

6. How can I clear the OBDII code U2104 on my Pontiac?

Clearing the U2104 code can be done using an OBDII scanner by selecting the option to clear codes after diagnosing and fixing the underlying issue causing the code.

7. Is it possible to repair OBDII code U2104 on a Pontiac myself?

Repairing code U2104 may require advanced diagnostic tools and knowledge of vehicle communication systems. It is recommended to consult a professional mechanic for proper diagnosis and repair.

8. Will disconnecting the battery reset OBDII code U2104 on a Pontiac?

Disconnecting the battery may temporarily clear the code, but if the underlying issue causing the U2104 code is not addressed, the code is likely to reappear once the vehicle is driven again.

9. How much does it typically cost to repair OBDII code U2104 on a Pontiac?

The cost of repairing code U2104 on a Pontiac can vary depending on the exact cause of the issue. It is advisable to get a diagnostic inspection from a qualified mechanic to determine the cost of repairs.

10. Can OBDII code U2104 on a Pontiac cause any long-term damage if left unrepaired?

If left unrepaired, code U2104 can potentially lead to further issues with the vehicle's communication systems, affecting its overall performance and safety. It is recommended to address the problem promptly to prevent any long-term damage.