U055C: Special Purpose Vehicle Control Module C Data Fault
The U055C code indicates that a control module on the vehicle's CAN bus has received invalid or corrupted data from the Special Purpose Vehicle Control Module 'C'. This module is a manufacturer-specific controller for specialized vehicle functions, and its exact identity varies by make and model. The fault occurs when transmitted data fails to meet expected format, has checksum errors, or the sending module operates outside design parameters per SAE J2012 for class B or C communications.
1. Commonly Affected Makes
This is a generic OBD2 code, potentially applicable to any manufacturer using this diagnostic standard.
2. Most Common Causes
- Internal failure of the Special Purpose Vehicle Control Module 'C' (microprocessor or memory damage)
- Electromagnetic interference on the CAN bus
- Abnormal resistance in CAN bus terminators (high or low impedance)
- Damaged, shorted, or high-resistance CAN bus wiring
- Corrosion, moisture, or bent pins in the module 'C' connector
- Software incompatibility or incorrect calibration of module 'C'
- Low battery voltage or poor ground at the sending module
3. Symptoms You Will Notice
- Check Engine Light or other warning lights illuminated
- Malfunction of systems controlled by module 'C' (e.g., special vehicle functions)
4. Step-by-Step Diagnosis
Scan for all stored codes and freeze frame data
Inspect CAN bus wiring and connectors for damage, corrosion, or loose connections
Check battery voltage and ground circuits for module 'C'
Test CAN bus resistance and signal integrity with an oscilloscope
Verify module 'C' software version and compatibility
If all else fails, replace module 'C' and reprogram if necessary
5. Frequently Asked Questions
Is it safe to drive?▼
The severity is medium. You can drive short distances, but the affected systems may not function properly. Have it diagnosed soon to avoid further issues.
How much does it cost to fix?▼
Costs vary widely depending on the root cause. Simple wiring repairs may cost $100-$300, while module replacement can range from $500 to $1500 including parts and labor.