U0662Lost Communication With Right Rear Temperature Actuator B
- Generic OBD-II code · Network
- How the car detects it
- With four rear temperature actuators, A and B on each side, plus front units, a climate system may run many look-alike motors on LIN, where one master serves up to 15 slaves. Identical parts must be told apart, either by part variant or by position detection along a daisy chain, as the LIN article explains. That makes right rear actuator B prone to a specific trap: a new or swapped unit that was never assigned its address answers on the wrong identifier, and the master logs U0662 although the part works. No maker documents this code publicly. A genuine loss only affects the fine mixing on the right rear side; actuator A keeps basic control there. Chips such as NXP's MM908E626 show the usual three-wire hookup of supply, ground and LIN.
- What you may notice
- Right rear temperature imprecise or slow to settle
- Code appears right after an actuator was replaced
- Likely causes
- PossibleReplacement or swapped actuator B without the correct LIN address
- PossibleActuator B electronics failed
- RareOpen supply, ground or LIN pin at actuator B
- 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.