U0121 Chevrolet Code - Lost Communication With Electronic Brake Control Module
Quick Answer
Modules connected to the high speed General Motor Local Area Network (GMLAN) serial data circuits monitor for serial data communications during normal vehicle operation. Common causes include Faulty Electronic Brake Control Module (EBCM), EBCM harness is open or shorted, EBCM 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
- U0121 Chevrolet indicates Lost Communication With Electronic Brake Control Module.
- Common causes
- Common causes include Faulty Electronic Brake Control Module (EBCM), EBCM harness is open or shorted, EBCM 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.
Code U0121 Chevrolet Description
What are the Possible Causes of the DTC U0121 Chevrolet?
- Faulty Electronic Brake Control Module (EBCM)
- EBCM harness is open or shorted
- EBCM circuit poor electrical connection
How to Fix the DTC U0121 Chevrolet?
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.
Code Tech Notes
2007-2010 Chevrolet Avalanche
2007-2010 Chevrolet Corvette
2007-2010 Chevrolet Silverado
2007-2010 Chevrolet Suburban
2007-2010 Chevrolet Tahoe
2008-2010 Chevrolet Silverado Hybrid
2008-2010 Chevrolet Tahoe Hybrid
Chevrolet Factory Service Bulletin OBDII Code U0121
What is the Cost to Diagnose the Code?
Labor: 1.0
To diagnose the U0121 Chevrolet 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.
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Frequently Asked Questions about U0121 Chevrolet Code
1. What are common symptoms of OBDII code U0121 in a Chevrolet related to lost communication with the Electronic Brake Control Module (EBCM)?
- Common symptoms include illuminated ABS and traction control warning lights, loss of ABS functionality, and potential issues with brake system performance.
2. What are some possible causes of the U0121 code in a Chevrolet indicating lost communication with the EBCM?
- Potential causes include damaged wiring or connectors between the EBCM and other modules, a faulty EBCM, low battery voltage, or a malfunctioning CAN bus network.
3. How can I diagnose the U0121 code in my Chevrolet related to communication loss with the EBCM?
- Diagnosis typically involves using a professional OBDII scanner to retrieve the specific trouble codes, checking the wiring and connectors for any visible damage, and testing the EBCM and related components for proper operation.
4. Can I drive my Chevrolet with the U0121 code for lost communication with the EBCM?
- While the vehicle may still be operable with this code, it is not recommended to continue driving without addressing the underlying issue as it can affect the ABS system's functionality and potentially compromise safety.
5. How can I repair the U0121 code in my Chevrolet due to lost communication with the EBCM?
- Repair methods may include repairing or replacing damaged wiring, ensuring proper connections, addressing any battery voltage issues, and replacing the EBCM if necessary.
6. Is it possible to reset the U0121 code in a Chevrolet without fixing the underlying issue?
- While clearing the code temporarily may be possible using an OBDII scanner, the issue causing the lost communication should be diagnosed and repaired to prevent the code from reoccurring.
7. Are there any DIY repair tips for addressing the U0121 code related to lost communication with the EBCM in a Chevrolet?
- DIY enthusiasts can start by checking the wiring and connectors for any visible damage, ensuring proper battery voltage, and consulting a repair manual or online resources for specific troubleshooting steps.
8. How much does it typically cost to repair the U0121 code in a Chevrolet caused by lost communication with the EBCM?
- Repair costs can vary depending on the specific cause of the communication loss, but expenses may include parts such as wiring harnesses or an EBCM, labor charges, and diagnostic fees from a professional mechanic.
9. Can weather conditions or environmental factors contribute to the U0121 code in a Chevrolet?
- Extreme weather conditions, moisture, or exposure to environmental elements can potentially damage wiring or connectors, leading to communication issues and triggering the U0121 trouble code.
10. Will the U0121 code in a Chevrolet reset itself after the underlying issue is fixed?
- In some cases, the code may clear on its own after the repair is made and the vehicle is driven through a few drive cycles. However, it is recommended to use an OBDII scanner to clear the code manually to ensure it does not return.
Discuss the causes and fixes for U0121 Chevrolet OBDII Code
-
i have caprice 2011 v8 when i test it then shows code u0121 .
the engine running about 2 seconds and turn off automatically ,
i change ECU , But the problem .
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