Network, generic

U0164 Lost Communication With HVAC Control Module

Check engine lightOn
EmissionsNot relevant
Drive cycleNot required
Limp modeNo

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.

Likely causes

Loose or spread terminals at gateway or inline bus connectors
HVAC module without power or ground
Incomplete module configuration or hung module, cleared by battery reset (Ford)
HVAC control module faulty

Symptoms

  • 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

Repair estimate

DifficultyMediumWorkshop job
Parts and labour€40–900
Time0.3–3 h

Typical range across vehicles; the real cost depends on what the testing finds.

Parts involved

hvac control modulecan bus wiring

Related codes

U0165U010FU0424U0324U0140

References: gsi.ext.gm.com, static.nhtsa.gov, static.nhtsa.gov, static.nhtsa.gov.