U0164: Lost communication with the HVAC control module
The vehicle network is not receiving messages from the heating and air conditioning module. The car drives fine, but climate control may not respond.
| Code | U0164 |
|---|---|
| System | Communication network |
| Group | U01xx, Lost communication with control units |
| Type | Generic: it means the same on every make |
| Can you keep driving? | Yes, no rush |
What U0164 means
The HVAC module controls heating, air conditioning, the blower fan and where the air goes. This code means it has stopped talking to the other control units over the data network. The engine is unaffected, but comfort and sometimes demisting are.
Most common causes
- Low or unstable battery voltage
- Blown fuse for the climate module
- Loose or corroded connector on the control panel or module (common after replacing the radio or removing the console)
- Poor ground on the module
- Damaged network wiring behind the dashboard
- Faulty climate control module or panel
Symptoms
- Climate control panel blank or unresponsive
- Air conditioning or blower fan not working
- Temperature or air distribution cannot be changed
- Windscreen demisting not working properly
Can you drive with U0164?
Yes, no rush You can drive normally and fix it at your convenience. However, if you cannot demist the windscreen, avoid driving in rain or cold weather until it is repaired.
Open the bonnetthe in-depth explanation
How to check it
Check whether the blower works at any speed and whether the panel lights up: that helps the garage tell a power fault from a module fault. Also see whether other U codes are stored at the same time.
How to read and clear U0164 with Final OBD
Plug an OBD2 scanner in under the steering wheel, switch the ignition on and open Final OBD. Under Faults you’ll see U0164 with its description and whether it’s confirmed, pending or permanent.
If the engine stores it over standard OBD, with FREE you read this code with its explanation for nothing and clear it. With PRO you also read the faults of every control unit and clear them in all of them.
Clearing the code only turns the light off: if the cause is still there, it comes back. Clear it once it’s fixed, and not right before an inspection. It’s all in how to read and clear fault codes and in inspections and OBD.
Similar codes
- U015B The power steering control unit B is not answering on the car network
- U0161 The compass module is not answering on the car network
- U0162 The navigation display module is not answering on the car network
- U0163 Communication with the navigation unit has been lost
- U0165 The climate control control unit (rear) is not answering on the car network
- U0166 The auxiliary heater control unit is not answering on the car network
- U0167 The vehicle immobiliser control unit is not answering on the car network
- U0168 Lost communication with the vehicle security module (immobiliser)
- U0100 Lost communication with engine control module (ECM/PCM A)
- U0101 Lost communication with transmission control module (TCM)
- U0102 Lost communication with transfer case control module
- U0103 Lost communication with the gear shift module
What does code U0164 mean?
The HVAC module controls heating, air conditioning, the blower fan and where the air goes. This code means it has stopped talking to the other control units over the data network. The engine is unaffected, but comfort and sometimes demisting are.
Can you drive with U0164?
You can drive normally and fix it at your convenience. However, if you cannot demist the windscreen, avoid driving in rain or cold weather until it is repaired.
How do you clear U0164?
With an OBD2 scanner and an app like Final OBD, which clears it for free if it’s stored by the engine control unit. But clearing it only turns the light off: if the cause isn’t fixed, U0164 comes back.
Read it on your car
Final OBD reads and clears engine faults through standard OBD for free, each one explained in plain English. With PRO it also reads the faults of every control unit, each make’s own codes included, and clears them in all of them.
