U065A: Lost Communication With Right Front Temperature Actuator

What it means

A control module has stopped receiving expected network messages from the right front temperature actuator. The effect on cabin temperature control depends on the vehicle's HVAC design.

How it works

The right front temperature actuator controls the blend of heated and cooled air for the right front HVAC zone. U065A sets when a control module stops receiving the actuator's expected network messages, so the right front temperature setting may not produce the requested air temperature.

Common causes

Most likely first.

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

Symptoms

• Warning light or message related to the HVAC system
• Right front air temperature may not respond as commanded

How to diagnose it

1. Scan the HVAC and other modules for freeze-frame data and related communication faults, checking whether the right front temperature actuator is the only missing device.
2. Change the right front temperature setting through its range and check for an air-temperature response or actuator data on the scan tool.
3. Inspect the right front temperature actuator connector and harness for loose pins, corrosion, chafing, or damage near the actuator.
4. Check the actuator's specified power and ground, because a supply fault can make the actuator disappear from the network.
5. Test the actuator's network wiring for opens, shorts, or poor connections to the manufacturer's specification before considering actuator or module replacement.

Common fixes

• Reconnect or secure the right front temperature actuator connector.
• Repair damaged wiring or corroded terminals in the right front actuator circuit.
• Restore the actuator's power or ground after locating the supply fault.
• Replace the right front temperature actuator or its module only if circuit checks confirm the unit has failed.

Can I keep driving?

Driving is generally possible if the fault only prevents right front temperature adjustment. Make sure the HVAC can still keep the windshield clear; do not continue if poor visibility makes driving unsafe.