Lost Communication With EV Thermal Pump Module
The U0229 code means the vehicle's onboard diagnostic system has detected: Lost Communication With EV Thermal Pump Module. This is a moderate severity code.
- Keep driving?
- Short distances only
- DIY difficulty
- hard
- Estimated cost
- $500 - $2,500 (parts and labor)
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
- Heat pump not functioning for cabin heat
- Reduced heating efficiency in cold weather
- Excessive range loss in winter
- Climate using resistive heat only
Probable Causes (Ranked by Likelihood)
- Failed heat pump module Very High
- Refrigerant leak in heat pump system High
- CAN bus communication fault Moderate
- Heat pump compressor failure Low
Step-by-Step Diagnostic Procedure
-
Check heat pump refrigerant level
-
Scan heat pump module for fault codes
-
Test CAN bus communication at module
-
Inspect heat pump compressor operation
Frequently Asked Questions
Can I drive with U0229?
Short distances. Cabin heat works but uses resistive heating, reducing range significantly in cold weather.
What causes U0229?
Most commonly a failed heat pump module or refrigerant leak.
Why does this affect range?
Heat pumps are 2-3x more efficient than resistive heaters for cabin heating.
Sources
This page is built from documented references. Verify against your own service info before repair work.
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