Control Module Calibration Communication Bus Off
The U0629 code means the vehicle's onboard diagnostic system has detected: Control Module Calibration Communication Bus Off. This is a moderate severity code.
- Keep driving?
- Short distances only
- DIY difficulty
- hard
- Estimated cost
- $150 - $600
Network codes mean modules are not communicating. You need a scanner that reads all systems to find the problem.
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Common Symptoms
- Engine performance reduced
- Transmission shifting abnormally
- Fuel economy decreased
- Emissions test failure
Probable Causes (Ranked by Likelihood)
- Module calibration file mismatch Very High
- Incomplete software update High
- Wrong calibration loaded after repair Moderate
- Module replaced with incorrect part number Low
Step-by-Step Diagnostic Procedure
-
Verify module part number matches vehicle
-
Check for available software updates
-
Reprogram module with correct calibration
-
Confirm VIN matches module programming
Frequently Asked Questions
Can I drive with U0629?
Check the severity. If it affects safety systems like stability control or braking, limit driving to short distances. Comfort features like heaters or parking assist are safe to drive with.
What causes U0629?
Most commonly a faulty control module calibration or damaged wiring in the communication circuit to that module.
How much does it cost to fix U0629?
Typical repair costs range from $150 - $600 depending on whether the module or just wiring needs repair.
Sources
This page is built from documented references. Verify against your own service info before repair work.
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