U010F: Lost Communication With Air Conditioning Control Module

What it means

A control module has lost communication with the air conditioning control module. Climate control functions may be affected, depending on the vehicle.

At a glance

• Usually lights the warning light of the system that lost communication

How it works

The air conditioning control module coordinates climate-control functions and communicates their status to other vehicle modules. U010F sets when another module no longer receives expected network messages from the air conditioning control module. It does not identify a refrigerant, compressor, or other air-conditioning fault by itself.

Common causes

Most likely first.

1. Loss of module power or ground
2. Open, shorted, or damaged communication wiring or connector
3. Module or gateway fault

Symptoms

• Climate control functions may be unavailable
• Warning lights or messages
• Communication faults in other modules

How to diagnose it

1. Save the all-module scan and freeze-frame data, noting which modules report the lost link and whether the air conditioning control module responds.
2. Check the relevant fuses and inspect the module's power and ground connections for a loose or corroded connection.
3. Inspect the air conditioning control module connector and network wiring for damage, moisture, or loose pins.
4. Check climate-control operation and scan for related HVAC codes to distinguish a communication loss from a separate cooling-system fault.
5. If power and ground are present but the module remains offline, test its network circuit and gateway path to the manufacturer's specification.

Common fixes

• Repair a poor battery connection or weak system voltage if it is disrupting module communication.
• Replace a failed fuse or repair the air conditioning control module's power or ground connection.
• Repair damaged network wiring and clean or secure the module connector.
• Repair a gateway fault if testing shows it is blocking the air conditioning module's messages.
• Replace or reprogram the air conditioning control module only after its wiring and supply circuits pass testing.

Can I keep driving?

The code generally does not make the vehicle unsafe to drive, but climate control may be unavailable, including demisting or defrosting support. Do not drive if you cannot keep the windscreen clear.