I guess you are talking about a M103? The crankshaft position sensor comes from the rear of the engine (engine bellhouse, above starter) and goes to the ignition modul. It is necessary for the engine to run. The camshaft position sensor comes from the front of the engine. It is not necessary for the engine to run but serves diagnostic purposes only (measuring ignition retard?).
Regards, Bruno

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1992 300TE 160 kmiles