U0325
Software Incompatibility With Auxiliary Heater Control Module
What it means
U0325 means Software Incompatibility With Auxiliary Heater Control Module.
Where it lives
For U0325, the part to look at first is the module named here.
Check these first
- Software in the Auxiliary Heater Control Module that does not match the rest of the vehicle
- The Auxiliary Heater Control Module replaced without programming to the vehicle
- Corrupted or outdated calibration in the Auxiliary Heater Control Module
- A module programming step that did not complete
What to do next
- Read stored codes on every module and note the mismatched part numbers
- Record the software and calibration part numbers in the Auxiliary Heater Control Module
- Reprogram the Auxiliary Heater Control Module with the latest calibration for the vehicle
- Check for a service bulletin that covers the Auxiliary Heater Control Module software
- Replace the Auxiliary Heater Control Module if programming will not complete
- Clear the code and retest
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Updated
Generic SAE J2012 definition. Last updated 2026-10-10.