Défaut ailleurs dans la boîte provoquant le mode dégradé

A transmission in a protective default because of a fault it has already stored, so subsequent codes describe the protection rather than anything newly wrong. The vehicle is behaving as designed — locked in one gear, refusing lock-up, holding a fixed line pressure — and the codes that follow are consequences.

This is the reason code order matters here more than anywhere. A gearbox in limp mode will produce ratio errors, shift performance faults and pressure codes simply because it is no longer shifting normally, and each looks like an independent fault. Chasing the newest code first is exactly wrong; the oldest one is the cause and the rest are its shadow.

Freeze frame data is what separates them. The originating fault has a frame describing normal driving; the consequential ones have frames describing a vehicle already in default. Clear everything, drive, and read again — what returns first, and alone, is the real fault. Resist replacing parts named by the consequential codes, which is how a solenoid or a speed sensor gets fitted to a transmission whose actual problem was low fluid.