Mounted on top of the idle air system on my 164E, just above the idle air adjustment, sits what appears to be a solenoid activated valve (it could be a sensor, I suppose). On my car, the normal wire connections evidently broke off and a previous owner has soldered the wires in place. I have followed one of the wires to ground, but I don't know where the other wire is connected. I have a good service manual for the car and it describes virtually every component in the idle air system in intricate detail. The solenoid is pictured in the manual, but it is never mentioned or described. What is the purpose of this unit? What is it called? Are replacements available?