U0164Network Communication

Lost Communication With HVAC Control Module

U0164 means a module has lost communication with the HVAC control module over the CAN bus. Heating and air conditioning controls may not respond. It usually points to a wiring, power, ground, or connector fault.

🚗 Use caution. Climate control may not work, but normal driving is usually unaffected.

MEDIUM

severity

🎯 Top Causes, Ranked by Likelihood

#1Wiring, connector, or CAN bus fault$50-$500

45%

Damaged or corroded wiring to the HVAC module.

#2Power or ground fault$50-$400

30%

Blown fuse or poor ground at the module.

#3Failed HVAC control module$200-$800

15%

The climate control module itself has failed.

🩺 Common Symptoms

Climate control not responding
No heat or air conditioning
HVAC display blank
Warning lights
Other U-codes stored

💰 Repair Cost: DIY vs Shop

DIY Cost

$50-$400

Shop Cost

$150-$800

📋 Free OBD2 Code Cheat Sheet

The 50 most common codes with likely cause and DIY fix cost. Sent once, no spam.

🔧 How to Diagnose U0164

1Check fuses, power, and grounds for the HVAC module

2Inspect CAN wiring and connectors at the module

3Scan all modules for lost-communication patterns

4Back-probe the CAN bus for correct signal

❓ Frequently Asked Questions

Can I drive with U0164?

Usually yes, but climate control may not work. Diagnose it when convenient.

What causes U0164?

Wiring, connector, or power/ground faults at the HVAC module, most often.

Why won't my AC work with U0164?

The HVAC module controls the climate system. When it drops off the bus, the controls stop responding.

🔗 Related Codes

U0100U0140U0155U0184