Megane 1.5 dCi - "Injection" warning

[AlanTR]

I'm getting a Check Injection warning on a 2004 Megane Dynamique 1.5 dCi (86 bhp). It comes up occasionally and the car seems to be performing ok.

Does anyone know what this alarm actually indicates? What kind of injection system fault will cause this fault indication?

[Skidms9]

The most common cause is 1 or more failed glow plugs. A DTC test would be a good place to start but if you can't get to a code reader then a test the glow plugs would be my next step.