recently the 740 I drive has been idling poorly. I checked the OBD and get the following code: 2-2-3 =signal missing to/from IAC (idle control valve). I took the valve out and cleaned it, and I checked for continuity and also applied voltage to the valve. I am thinking that if the valve works (opens and closes with voltage applied) then it must be good, right? then again, is there a range of voltage that the valve is programmed to function within?
I also read fault code 2-3-2-(fuel trim too rich or too lean) so I took a long handled screw-driver and applied it to the base of the injectors, one by one to listen to the click-click of the electrical impulses, to determine if an injector was erratic- maybe that could be causing the oxygen sensor to malfunction- the accessory light comes on after starting the engine, but goes out after about five minutes. So the code may be legit about the sensor being on the verge of not working- Could this be a cause of the poor idle and the malfunction of the IAC? There are some other issues I will relate later, but I want to find out about this one first.
BTW, I replaced the IAC about two years ago, with an item I picked up at PNP. It's worked well for that length of time.I would think the life span of this valve would be pretty long.
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89-740 GLE;91-940 Sedan ;98-V90 Wagon ___ all running well