cat info for Japan spec. BMW owners

[shogun]

BillR posted this info on roadfly in connection with some trouble a friend here in Japan has with his japanese spec. E32 750iL with the M70 engine. This might be also interesting for owners of E34 exported from Japan to Australia/Phil's and NZ, the major export markets. Our friend here imported a US spec. cat from a dealer in Arkansas, but this does not have the thread for the special temp. feeler at the end of the cat.
Here copies of BillR's info:

Japan was one of the few markets that required
temp sensor on the back of the cats to warn you when the cats are overheating... this isn't a bmw only thing, i'm pretty sure its all cars in the japan market, I've seen a number of gray market toyotas and nissans with the same temp sensor on them. I suspect if you look at japans equivalent to the epa pollution rules for cars you'll see that theres a requirement for cat temp sensors as a safety device. A badly overheating cat will glow cherry red and ignite any paper or grass etc that its parked over.

Just for your info.

[shogun]

As today someone from Canada asked me this question again as he imported an E32 750iL from Japan and has the cat warning, here is a pic of the special relay for 870 degree Celsius which is located under rear seat driver side
ImageShack® - Online Photo and Video Hosting

Just pull it out and the problem is solved. But you could try to repair it. If you want a used one, you probably won't find these in N.A., I should have some used on stock.
Another solution:
the cable white/purple/yellow goes from this module to another plug on pin 20 to the CCM. If you cut off this cable and connect it to ground, that has the same effect.

Then download these Japanese spec wiring diagrams
https://skydrive.live.com/?cid=c83d0...21955&authkey=

[genphreak]

Good stuff- thank you. I'll document the arrangement on the M50 525i soon and post back. I have the 'Catalyst' error so it sounds like its the temp sensor. It'll be interesting to tet to see if the sensor is bad or the error is real (nad the Katalyst bad- I bet it is!)