porovaara

If you get a chance could you let me know what the tolerance ranges are on the Electronic Coolant Temp Sensor?

(also what book are you getting all this out of? guess i need a copy)

moribundman

I got that info from a German A4 repair manual. I haven't checked, but the Bentley should show the same info. It's just hard to find anything on the Bentley CD.

Anyway, I can give you some info. As I said earlier, check resistance between contacts 1 and 3 on the coolant temp sensor:

For every temperature, you should get a specific resistance (+/- a little bit):

Degr. F --> Resistance

32 --> 5.5k Ohm
50 --> 3.7k Ohm
68 --> 2.5k Ohm
86 --> 1.7k Ohm
104 --> 1.2k Ohm
122 --> 950 Ohm
140 --> 600 Ohm
158 --> 425 Ohm
176 --> 325 Ohm
194 --> 250 Ohm
212 --> 200 Ohm

porovaara

My sensor poles are labeled A-B and C-D. At 75 degrees A/B are waaaaaaay out of spec but C/D are pretty close to matching the above numbers at 2.0?.

This is good and bad, good because if C/D are akin to 1/3 then my old sensor is still good and bad because uh, well now, crap, it is probably the wiring?

moribundman

Yes, sure... Check your mail