copy paste from other forums
I decided to do a DIY accessible to anyone who wants to repair the song "Preheating control unit" 12217801200 or the Romanian code "glow plug relay" in my case 318d E46 facelift 4.2 PTR one.
We decided to investigate the relay after INPA (tester) gave me error all 4 spark plugs, their condition is ok after checking in advance.
The topic is addressed DIY and craftsmen who appreciate posts will still not invest in a new relay small amount of 300 USD.
In short, repair it (in most cases) requires tinning of wires inside the command module unstick the glow plugs.
1. Location is Relay by TIS (Warning facelift models only - NFL models have classic relay box above the brake servopompei) at the bottom left of the car under the intake manifold, near the steering column and dismantling access making it the most easy and hassle free car built under the elevator. Recommend removing the screws, then plug round (use force not imagination) and after you loosen the two socket higher because you have more room for maneuvering http://img715.imageshack.us/img715/4480/98gcqe.th.gif
2. Peel relay cover (by any method: screwdriver, knife, cutter) taking care not to damage the electronic parts inside http://img196.imageshack.us/img196/2...ge0450i.th.jpg
3. Peel conductors are those that connect the printer to the jack plate. Note position of wires to be replaced. All components are under a layer of sticky elastic protective gel. I removed the gel (only on the portion where I wanted to stick) using a cutter me a toothbrush and very carefully. I tried with 4 different types of solvents but I was unsuccessful. In the picture you can see November wires replaced. Suggest a strong letcon. http://img851.imageshack.us/img851/8...age0448.th.jpg
4. After checking with multimeter continuity links stopper new transparent silicone work to protect the future vibration and weather. Then also sticks with silicone lid and fasten with a mouse (just in case)
5. I previously bought a new relay but I had the chance to try on the repaired several weeks. I had no trouble turning chilly -3 degrees in my INPA Austria nor never gave any error.