VRCustoms

There a lot of BMW diesel with that faulty preheating unit.

Here is how you can repair your BERU preheating unit. It is called also glow plug relay, but it is not relay any more, because it is not using anymore relays.

One indicator for this unit is if you connected to obd tester (inpa or autocom), you will see that all 4 or 6 (depending on number of cylinders)  glow plugs are intermittent or faulty. Usually there are not all 4 or 6 faulty.

If you want to check your glow plugs you will need to remove intake manifold. Resistance should be between 0-1 ohm. But you can checked them on modules connector. First disconnect it and than you will see 4 or 6 wires who are going to intake manifold. Put one on pin and one on the ground and check resistance. If all 4 or 6 are having resistance in range between 0-1 than it is something wrong with glow plug relay.

It is very hard to access. Module is located under oil filter.I think that module is located there, because copper is expensive so, they didn’t need long cables- cheaper production.

 

You will need to cut top cover, be careful.

 

Here I noticed that small aluminium wires are burned or in really bad shape. This is main power supply for the module and plugs. And look how tiny wires are. German quality…

 

I removed jelly silicone carefully with knife and screwdriver and tweezers.

 

 

Then I cleaned it with alcohol and slowly   sanded it  until I get to the copper.

You will need a lot of heat to solder terminals. You can remove pads from pcb, because they are soldered on pcb.

 

With flux paste you can solder terminals.

 

I used big copper wire and soldered it.

You can protect pcb with spray. It will be protected from water.

After that I didn’t screwed it back in place. I tested it so I secure it with zip ties and connected ground cable on screw holes. Then I erased all errors with INPA tool.

 

If modules works OK, then just seal it with silicone or better gasket sealent and avoid pcb board, because some silicones are conducted and they can cause you a lot of problems.

You can also check all remaining 4 or 6 wires if they are OK. Some are burned in modules.

Hope this post will help you  and save you 100 bucks.