The GP module is prone to failure. IMHO not replacing the GPU could have some negative consequences. Also, check the coolant temperature using the hidden menu or a OBD reader, anecdotal evidence suggests that a broken thermostat (running only a bit over 60 degC) can lead to GPU ( and GP) failure.

The GPU is attached to the engine block under the intake manifold. Many remove the manifold to access the GPU. I replaced mine, w/o removing the IM, in an underground parking using a long 1/4" extension and a set of magnetic sockets. There is a video on UTube showing how to do it. The module is about $120 and if you can DIY, not an expensive fix.

Replacing the thermostat is more involved but still achievable for most who have a space and a well filled tool box.

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2003 4.4i black ext./black int./black headliner (kid's runabout)
2014 535d X-drive, M package, silver/black interior

Sold but not forgotten:
2009 E70 35d, black ext./black int./black headliner (sold 2021)
2006 4.8iS Le Mans blue/cream int./black headliner, SOLD in 2012 sadly...

Other hardware:
2015 Cayenne S (wife's new DD and definitely wroooommmmm)
2016 Tundra 1794 edition crew cab, luxo hauler
2005 Tundra crew cab, weekend hauler. Sold after 150k very happy miles.