Hi,

I'm new to the Volvo world. I've been fairly active working on my 87 VW Westy but definitely have some things to learn. I recently purchased a 92 740, in really good shape, 122K. With the help of this board, a good friend, and fcpgroton, it's running well. One problem I'm trying to chase down is FI error code 2-4-1, which indicates possible EGR issues (and illuminates the check engine light). The vehicle is running well, so the initial thought was the temperature sender was malfunctioning (Since it is only reporting, not controlling?). The Bentley (for the 240 -- seems like that and this board are all one needs) suggests impedance testing the temp sender. I tested the installed unit by decoupling the bail connector and using my multimeter to test. I'm a bit confused with the results and I think this has to do with several things (one of which may be my misunderstanding of my multimeter). I tested the unit about 15 minutes after I turned the vehicle off. My meter is selected to the setting which measures Ohms, and was in the 200k position. I got a reading of 58. As the temperature cooled, additional readings showed progressively higher values (62, 68.5, 72, 75...) I stopped there. I also have a new temp sender. The reading is 177. This unit has not been installed. The Bentley defines valid ranges of 500-1000 ohms. So, my first question is, how to I interpret my MM readings and is the existing temp sender faulty? Secondly, is the above logic sound? I'd hate to install a new (~180usd) unit if the installed unit is fine.

Thanks in advance