My 2004 E46 320d M47TU doesn't start as well as it should from cold. On INPA I get an error code for all the glowplugs. I replaced the plugs with brand new BERU's recently, the faults occurred straight away.
I've been told this could be a fault with the glowplug controller unit, located on the side of the engine next to the starter motor I believe. Does anyone know of anything else it could be and/or if its possible to test the glowplug controller?
Also, any tips on changing it would be appreciated, apparently its a pig of a job :(
Edit: Looking on RealOEM I assume its the "preheating control unit", part number: 12217801200 can anyone confirm this?