Trouble Judgment
WARNING: This page is about a different car, the 2015 Mitsubishi Lancer. However, it is still accessible from the selected car via links, so may be relevant.
The A/C controller assembly (A/C-ECU) or heater controller assembly (A/C-ECU) (vehicles without A/C) receives air conditioning operation-related signals from the SRS-ECU via the CAN bus lines. If any of the air conditioning control-related signals from the SRS-ECU cannot be received, the diagnostic trouble code U0151 is stored.