U0661Lost Communication With Right Rear Temperature Actuator A
- Generic OBD-II code · Network
- How the car detects it
- A right rear temperature actuator is only fitted where the rear seats are split into left and right climate zones, as in four-zone systems of large sedans, SUVs and vans. Actuator A on the right is the counterpart of U065F on the left, so when this code is stored the passenger behind the front passenger seat loses temperature control while the left rear zone still works. No maker documents U0661 publicly; GM's bulletin 23-NA-206 names only the left-hand rear actuators. Hanon's US 11,305,608 shows the door arrangement that such zones rely on. Because both rear sides often share one harness and LIN segment, a single right-side code points toward the actuator itself; right and left together point toward the common wiring or the master.
- What you may notice
- Right rear zone stays at one temperature
- Rear right temperature buttons have no effect
- Left rear zone continues to work normally
- Likely causes
- LikelyRight rear temperature actuator A failed
- PossibleActuator plug in the right rear duct area loose or corroded
- RareShared rear LIN segment faulty (then usually several rear codes)
- Repair
- Hard · Usually a job for a workshop.Typical cost: €60 – €600
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.