U065FLost Communication With Left Rear Temperature Actuator A
- Generic OBD-II code · Network
- How the car detects it
- Vehicles with a separately controlled rear climate zone need their own temperature doors for the rear outlets, and in a split rear system the left side may use two of them, labelled A and B. Hanon's US 11,305,608 shows why two can be needed: one door ahead of the heater core and a second behind it mixing warm air into the rear cold-air duct. Which door counts as A is up to the maker. GM uses this code: bulletin 23-NA-206 lists U065F-00 in the body control module of the CT4, CT5, Corvette, Escalade, Tahoe, Suburban and Yukon from model year 2020 or 2021 on as a history code from software anomalies that turns on no lamp and may be ignored; if it is current, normal diagnosis applies. A real loss leaves the rear left air at one temperature.
- What you may notice
- Often none when the code is only stored as history
- Rear left air stays hot or cold
- Rear temperature control has no effect on the left
- Likely causes
- LikelySoftware timing between modules logs a false history code (GM)
- PossibleLeft rear temperature actuator A failed
- RareRear HVAC harness or connector damaged in the floor or rear quarter
- Repair
- Hard · Usually a job for a workshop.Typical cost: €0 – €600
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.