Crankshaft Position Sensor (CPS), Aftermarket - E30 325i, E34 525i, M20

This CPS sensor works on the front timing cover to read crankshaft position by sensing the teeth on the crank pulley.

There are very few items that can force an M20 engine to not start and the Crankshaft Position Sensor is one of them. The crank sensor (CPS) tells the ECU what position the cams and pistons are in in order to set timing for engine startup. Without engine position the ECU won't energize the ignition system to start. Sometimes the CPS may be dirty or mounted too far away from the crank pulley (or flywheel on early models) and it simply needs adjustment. Otherwise complete replacement is required.

This crank shaft sensor replaces the outdated / superseded BMW part # 12141720852 (12-14-1-720-852) and is the latest updated version from the manufacturer.

Note: if you have a smooth front crank pulley (no teeth) this is not the correct sensor for you. This is later-style sensor generally found on 1987+ E30 325i and 525i with Motronic 1.1 or 1.3 ECU. However, some very early 1986-1987 models had the older style crank sensor(s) mounted in the transmission and did not use this CPS.

Also used on 1988 325/528 “Super E” models.

This part is manufactured by an aftermarket supplier of European auto parts, including many sensors and electrical components. While not carrying OEM status, this part follows the design of the original very closely and uses similar materials. The brand may even be OEM to another manufacturer besides BMW. This aftermarket brand has a two year warranty - the same as Genuine BMW and OEM brands.