U055D: Invalid Data from Special Purpose Vehicle Control Module D
The U055D code indicates that a control module on the vehicle's communication network (typically the engine control module, transmission control module, or a central gateway module) has received invalid or corrupted data from the Special Purpose Vehicle Control Module 'D'. This module 'D' is an auxiliary or specialized device not part of standard vehicle systems, such as emergency equipment, special conversions, or fleet systems. The communication failure occurs on the CAN (Controller Area Network) or LIN bus, preventing the transmitted information from being correctly interpreted by the receiving module.
1. Commonly Affected Makes
This is a generic OBD2 code, potentially applicable to any manufacturer using this diagnostic standard.
2. Most Common Causes
- Faulty Special Purpose Control Module 'D' (internal damage, corrupted firmware)
- Electromagnetic interference in the communication bus wiring
- Abnormal resistance in CAN-H or CAN-L wires (corrosion, pinch, partial cut)
- Damaged or missing CAN bus terminators
- Low voltage at the transmitting or receiving module
- Moisture, corrosion, or bent pins in the module 'D' connector
- Software incompatibility between modules after an update or replacement
3. Symptoms You Will Notice
- Check Engine Light or other warning lights illuminated
- Malfunction of auxiliary equipment controlled by module 'D'
- Intermittent or complete loss of communication with module 'D'
- Possible drivability issues if module 'D' affects engine or transmission
4. Step-by-Step Diagnosis
Scan for all stored codes and document freeze frame data
Inspect the module 'D' connector for moisture, corrosion, or bent pins
Check CAN bus wiring for damage, corrosion, or shorts using a multimeter
Measure CAN bus resistance between CAN-H and CAN-L (should be ~60 ohms with terminators)
Verify power and ground at module 'D'
Check for electromagnetic interference sources near the wiring
If all else fails, attempt to reprogram or replace module 'D'
5. Frequently Asked Questions
Is it safe to drive?▼
The severity is medium. You can usually drive short distances, but the affected auxiliary equipment may not function, and in some cases drivability could be impacted. It's best to diagnose and repair promptly.
How much does it cost to fix?▼
Diagnosis typically costs $100-$200. Repair costs vary widely: cleaning a connector may be under $100, while replacing a special purpose module can range from $200 to $800 or more, depending on the module and labor.