Car goes into 'limp mode' with CEL soon after starting.

Car Check Engine Light (CEL) came on and car went into limp mode a few week ago. I checked the car: fluid levels normal, hose clamps tight, electrical connections tight. However, a single wire (tan or white with red stripe) with a plastic female connector was hanging between the firewall and the engine in the engine compartment. Mechanic and Ford service folks could not identify it. (See attached picture) After sitting overnight, the car started normally and ran fine for about 5 minutes, then CEL and limp mode again. I took it to an independent garage and they were unable to pull any error codes from the PCM (powertrain control module) using an OBD1 tester. The Ford dealership could not pull any codes either. I bought an Inova OBD1 reader and tried pulling codes. With key on engine off (koeo) I got a 111 code (all relays working?) And 10 (continue with next test?). With key on engine running (koer) the OBD1 produced no codes and the PCM appeared to lockup (radiator fan came on and ran continuously, CEL plus Battery light and Oil light on Dash). Had to disconnect battery to unlock. Incidence of limp mode is happening sooner and sooner as time goes on. Fuel line pressure seems normal ~40 PSI. I'm waiting for delivery of a refurbished PCM, but hope is fading. Help! Suggestions appreciated...