P0606: the engine's own control module has reported an internal fault
The engine control unit constantly checks its own internal workings, in the same way it checks the sensors around the engine, because a fault inside the module itself can be just as serious as a fault in any part it controls. This code means the module has found a problem with itself, in its processor or its memory, rather than in any sensor or actuator outside it. Unlike almost every other engine code, this one points at the computer rather than at the engine it's managing.
You might notice
- The engine warning light comes on
- The engine may run in a very limited way, or not start, since the module manages nearly everything about how it runs
- engine control unit
- — the computer that runs the engine
What the code itself says
P0606 is a powertrain (engine, gearbox and drive system) code, and the 0 after the letter means it is a generic code with a standard meaning.
Grouped here as: Engine computer — Faults inside the engine computer itself. That grouping is ours, to help explain the code. The code's official family is the letter at the start.
This page is generic. Your car isn't.
A code on its own only tells you what the sensor saw, not what's actually wrong — and that changes next to your other codes. Read this one together with the rest of your scan and we'll work out what's really going on.
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