OBD2 Code U0079: Reserved by SAE J2012
The U0079 diagnostic trouble code is reserved under the SAE J2012 standard and does not have a specific diagnostic definition in the current public specification. According to SAE J2012, codes U0070-U0079 are classified as 'Reserved by J2012,' meaning they are set aside for future use or standard expansions that have not yet been officially implemented. This code should not be confused with active diagnostic codes; its appearance may indicate a scanner communication issue with the vehicle's control module, outdated scanner software, or misinterpretation of CAN bus data.
1. Commonly Affected Makes
This is a generic OBD2 code, potentially applicable to any manufacturer using this diagnostic standard.
2. Most Common Causes
- OBD-II scanner with outdated software that cannot properly interpret reserved codes
- Temporary interference or failure in CAN bus communication during scanning
- Vehicle control module with non-standard programming or aftermarket modifications
- Use of a diagnostic tool not compatible with the latest SAE J2012 revision
- Intermittent connection at the Data Link Connector (DLC) causing read errors
3. Symptoms You Will Notice
- Check Engine Light may illuminate
- Scanner displays U0079 but no drivability issues are present
4. Step-by-Step Diagnosis
Verify that the scan tool is up-to-date with the latest SAE J2012 definitions
Check for loose or damaged pins at the DLC and ensure a secure connection
Clear the code and re-scan to see if it returns; if not, it may be a transient communication glitch
If the code persists, consult the vehicle manufacturer for any proprietary definitions or updates
5. Frequently Asked Questions
Is it safe to drive?▼
Yes, it is generally safe to drive. The code is reserved and does not indicate an active component failure. However, if the Check Engine Light is on, have the system checked to rule out other issues.
How much does it cost to fix?▼
Typically, no repair is needed. If the code is due to a scanner issue, updating the scan tool software may cost $50-$150. If a vehicle module update is required, dealer service may range from $100-$300.