At approximately 43,044 miles, my 2021 Audi A7 55 TFSI e quattro (PHEV) was diagnosed with a failed N632 coolant changeover valve — a component of the PHEV thermal management heating circuit. The vehicle has a complete, documented service history with no maintenance gaps. The N632 is an electronically controlled valve that routes coolant between the combustion and hybrid/electric circuits and is essential for cabin heating in EV mode, battery pre-conditioning, and engine warm-up. Failure of this valve can result in loss of cabin heat, coolant leaks into the engine bay, and potential cascade of electrical faults if coolant migrates into the wiring harness. The repair estimate is $1,700. The factory warranty, Audi Care plan, and third-party extended service contract (United Car Care Protection Plus) have all denied coverage. This failure on a low-mileage PHEV with full service history suggests a premature component defect in Audi's PHEV thermal management system. I am requesting NHTSA investigate whether this constitutes a pattern of failure across 2021 Audi PHEV vehicles.
- NHTSA ID
- 11734901
- Incident
- Apr 15, 2026