U062E: Lost Communication With A/C Refrigerant Expansion Valve Actuator

What it means

A control module has stopped receiving expected network messages from the A/C refrigerant expansion valve actuator. The effect on refrigerant flow and A/C operation depends on the vehicle's system design.

How it works

The A/C refrigerant expansion valve actuator meters refrigerant into the evaporator or other controlled circuit to regulate cooling. The control module expects network messages from the actuator, and U062E sets when those messages stop arriving. The system may be unable to control refrigerant flow correctly and can limit A/C operation.

Common causes

Most likely first.

1. Bus wiring open or shorted
2. Module without power or ground
3. Module failed

Symptoms

• A/C may not operate as intended
• Warning light or message related to the A/C system

How to diagnose it

1. Scan all modules and save available event data to check whether the expansion valve actuator fault is isolated or part of a broader network issue.
2. Check A/C live data for expansion valve actuator communication, requested operation, and reported status if available.
3. Inspect the actuator connector and accessible communication wiring for loose pins, corrosion, moisture, or damage.
4. Check the actuator's power and ground against the manufacturer's specification.
5. Test the actuator communication circuit for opens or shorts using the vehicle wiring diagram and manufacturer's procedure.

Common fixes

• Clean and secure the actuator connector or repair damaged wiring.
• Restore the actuator's power or ground supply.
• Repair an open or short in the actuator communication circuit.
• Replace the expansion valve actuator if its wiring and supplies test correctly but communication remains lost.

Can I keep driving?

You can generally drive, but the A/C may cool poorly or stop working. Avoid relying on it for demisting, and have the system checked if cooling loss affects visibility.