I believe your car uses the 3 pin sensor for the temperature gauge & ac cutout, and the 1 pin for the engine computer. I'd take a peek at the wiring diagrams and compare wire colors to confirm.

My 91 603 uses a 2 pin sensor on the head, near the glow plugs for the glow plug system and dashboard gauge. There's another 2 pin sensor for the climate control / radiator fans, and the 1 pin sensor goes to the engine computer.

-J

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1991 350SDL. 230,000 miles (new motor @ 150,000). Blown head gasket

Tesla Model 3. 205,000 miles. Been to 48 states!
Past: A fleet of VW TDIs.... including a V10,a Dieselgate Passat, and 2 ECOdiesels.
2014 Cadillac ELR
2013 Fiat 500E.