What Does U0297 Mean?
Communication with the secondary AC to DC Converter Control Module B has been lost. In dual-converter systems, this module works alongside Module A to manage high-voltage power conversion and distribution.
Safety Warning
Vehicle may operate in limp mode with reduced power or may not start. High-voltage system work requires specialized training and equipment.
Common Causes
35%
Corroded or damaged connectors and wiring to converter module B
30%
Failed AC to DC Converter Control Module B
15%
Cooling system fault causing thermal protection shutdown
12%
Power supply issue to module B from distribution system
8%
Network communication fault on dedicated converter CAN bus
Diagnostic Steps
1
Step 1: Implement high-voltage safety procedures and verify proper 12V auxiliary power supply
2
Step 2: Compare operation with Module A - check if both modules show faults or only Module B
3
Step 3: Inspect Module B connectors for water intrusion, corrosion, or damage to pins and seals
4
Step 4: Test cooling system operation specific to Module B and verify coolant flow and temperature
5
Step 5: Measure high-voltage supply to Module B and test CAN communication circuits; replace module if power and communication are present
Estimated Repair Cost
$1,000 - $4,000
Parts + labor, varies by vehicle and location
Communication with the secondary AC to DC Converter Control Module B has been lost. In dual-converter systems, this module works alongside Module A to manage high-voltage power conversion and distribution.
The most common cause of U0297 (Lost Communication With AC to DC Converter Control Module "B") is: Corroded or damaged connectors and wiring to converter module B
Typical repair costs for U0297 range from $1,000 to $4,000, depending on the vehicle, location, and whether you do it yourself or go to a shop.
Vehicle may operate in limp mode with reduced power or may not start. High-voltage system work requires specialized training and equipment.
Start by connecting an OBD2 scanner to read the code and any freeze frame data. Then follow the diagnostic steps specific to U0297 to identify the root cause.
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Quick Info
Category
Network
System
High Voltage Power Conversion System
Difficulty
Type
Generic (SAE)
Recommended Tools
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