Glow plugs staying on

[4KTD]

I have a 1993 Golf TD 1.9L AAZ. My glow plug relay died and I just replaced it. I noticed that the glow plugs stay energized for about 3 minutes after the engine is running. I have the GP relay and GP control module as seperate units. Does anyone know if it's normal to stay on for that long after starting?  My next step is to change the ECT sensor and check the wires related to the ECT sensor as well.

[Vincent Waldon]

Totally normal for AAZs...it's called afterglow and was implemented to improve cold engine driveability and reduce emissions.

TDIs do it too, although the ECU switches off the afterglow above 2400 RPM.