U0164Lost Communication With HVAC Control Module
- Generic OBD-II code · Network
- Turns on the check-engine light
- How the car detects it
- U0164 is stored by any module that stops hearing the HVAC control module, the unit that runs blower, flaps and temperature selection. GM documents two monitors in its 2025 tables (25OBDG03B): the body control module watches several HVAC frames and flags a gap longer than 12.5 s at 11-18 V, and the central gateway reacts after 6.5 s once a frame is overdue by 2.5 times its period; both are Type B, so the MIL can come on after two trips. Ford SSM 47040 (Escape 2017-2018) finds U0164 in the BCM and starts with a battery reset; GM PIT5586G and Stellantis case S2308000122 (Wagoneer) trace it to gateway or inline bus connectors. U0165 is the rear unit, U010F the A/C module. Climate controls go dead.
- What you may notice
- Climate control panel dark or not responding
- Blower, temperature or defrost stuck at last setting
- Check engine light on some GM models after two trips
- Code stored in several modules at once
- Likely causes
- LikelyLoose or spread terminals at gateway or inline bus connectors
- PossibleHVAC module without power or ground
- PossibleIncomplete module configuration or hung module, cleared by battery reset (Ford)
- RareHVAC control module faulty
- Repair
- Medium · Usually a job for a workshop.Typical cost: €40 – €900
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.