I don't know which 4-pin connector you are talking about?
The coolant temp sensor on the 16-vlv is a two pin connnector. I changed all of the sensors on my head two weeks ago w/ new parts.
I can read the schematics, but I am wondering if the feedback through a failed diode would screw w/ the CIS/EZL signals during normal operation !!!
1994 E500 (MY SUNDAY DRIVER)
1993 190E SPORTLINE LE W/ M104 SWAP
2000 BMW 528I (WIFEY'S CAR)
"Excuses are crutches for the unfounded."