U0164 Lost communication with the HVAC control module

Lost communication with HVAC control module

Severity not verified — if the car runs badly, have it inspected

Losing the climate controls alone is not a safety problem, but complaints show U0164 stored with many other modules during stalls and reduced power, so the severity depends on what else is stored.

It gets more serious if:

  • Inspect soon: Inspect soon if U0164 is stored with other lost-communication codes, or the vehicle has reduced power, stability or ABS warnings, or loses power.

Source: how we rate severity

U0164 in short

U0164 means other modules stopped hearing from the heating and air-conditioning control module. Alone it mostly costs you climate control. It often appears with many other U-codes, which points to a shared wiring or connector fault or weak battery power. If other warnings or power loss appear, get it checked soon.

The climate control module reports over the vehicle network. If its messages stop, other computers store U0164.

GM information for 2010-2015 Equinox and Terrain, and 2014 Impala, lists U0164 with a group of other U-codes and points at a corroded body harness connector or a pinched data line in the instrument panel harness. Complaints from Jeep, Chevrolet, Ford and Kia owners show U0164 stored with many other modules during stalls and warning-light showers.

Because it is so often one of many codes, read all codes before deciding what to chase.

Most likely causes

  1. Corroded connector or damaged harness shared by several modules

    Supported by vehicle data
    Why it ranks here
    GM information points to water at body harness connector X901 (Equinox, Terrain) and a pinched data line (Impala) when U0164 is stored with other lost-communication codes; only the NHTSA summaries were read.
    What would change this
    Rises if many modules lose communication together and a connector shows corrosion. Falls if only the HVAC module is affected.

  2. Weak 12-volt battery or voltage drops

    Possible — needs testing
    Why it ranks here
    One Kia owner was told by an independent mechanic the battery needed replacing after U0164 and other codes; this is a single report.
    What would change this
    Rises if the battery tests weak or the car has jump-start history. Falls if the battery and charging are good.

  3. HVAC control module fault

    Possible — needs testing
    Why it ranks here
    The code names the module, but AA1Car says a lost-communication code does not say which part failed.
    What would change this
    Rises if the climate controls are dead and power and ground are good. Falls if other modules are also offline.

What to test first

Start at step 1. Each result tells you what it means and where to go next.

  1. Read all stored codes and note whether U0164 is alone or stored with many other lost-communication codes.

    Low riskTool: OBD-II scan tool

    • IfMany modules show lost-communication codes

      It meansSuspect a shared harness, connector or power problem.

      Go to step 2

    • IfOnly U0164 is stored and the climate controls do not respond

      It meansSuspect the HVAC module or its supply.

      Points to: HVAC control module fault

  2. Check that the 12-volt battery tests healthy and the terminals are tight, then ask a shop to inspect the body and instrument panel harness connectors for water or pinching.

    Low risk

Symptoms

  • Climate controls not responding
  • Many warning lights or messages at once Gets more serious: stop and have it checked.
  • Reduced power or stall Gets more serious: stop and have it checked.

How to fix

  1. Check that the battery terminals are clean and tight.

  2. Ask a dealer whether a bulletin applies to your VIN.

On your vehicle

Chevrolet

  • 2010–2015 · Equinox

    Supported by vehicle data

    GM PIT5422 covers 2010-2015 Equinox (and Terrain) with U0164 among other U-codes and points to harness connector X901. Whether it is still current is not verified.

  • PIT5422Status unverified

    Intermittent MIL, inoperative interior lamps or liftgate with U-codes including U0164

    2010–2015equinox · NHTSA 10114581

    Inspect body harness connector X901 for water or corrosion and repair the connector and terminals. The same information covers GMC Terrain.

    We couldn't confirm whether this bulletin is still current, so it doesn't count as confirmation.

  • PIC5894Status unverified

    Multiple cluster warnings with U-codes including U0164

    2014impala · NHTSA 10113208

    Inspect for a pinched data link branch in the instrument panel harness behind the carrier.

    We couldn't confirm whether this bulletin is still current, so it doesn't count as confirmation.

  • U0155Lost communication with the instrument panel cluster

    Shares causes Supported by vehicle data

    GM bulletins list U0155 (instrument cluster) with U0164 as codes set together by one harness fault.

All Module network (CAN bus) communication codes

U0164 questions

Does U0164 mean I need a new climate control module?

Not necessarily. It often appears with many other codes from one wiring or power fault, so read every code and check power first.

Sources and review

  1. NHTSA complaint ODI 11246629: 2017 Jeep Cherokee — NHTSA (owner complaint)
  2. NHTSA complaint ODI 11755071: 2020 Chevrolet Malibu — NHTSA (owner complaint)
  3. NHTSA complaint ODI 11762384: 2023 Kia Niro — NHTSA (owner complaint)
  4. GM PIT5422: intermittent MIL, inoperative interior lamps or liftgate with U0164 and other U-codes (2010-2015 Equinox, Terrain) — NHTSA (manufacturer communication)
  5. GM PIC5894: multiple cluster warnings with U0164 and other U-codes (2014 Impala) — NHTSA (manufacturer communication)
  6. NHTSA complaint ODI 11756329: 2022 Kia Sorento — NHTSA (owner complaint)
  7. CAN bus U-codes — AA1Car Auto Diagnosis
Last reviewed
Written by
Saurabh K.
Editorial review
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