hello
i need some help for correct wiring of the trigger sensors on m50b25 with vanos.
the stock ecu is siemens ms40.1..crank and cam sensor have 4 wires 1 is the shield..the colors is black ,yellow and brown.which one is the signal ground and what power is needed?from what i found the crank is vr and cam hall it can be true this??
thanks a lot
The factory wiring diagram for these is a little confusing.
These are the relevant diagrams, it does say cam is hall and crank is vr.
ok i understand where i’m wrong.the vr sensor is 5v??12v is the hall
thanks i give a try
VR sensors are normally 2 wire and have no power supply as they generate their own voltage. Hall sensors are notmally12v.
Then why 3 wires?so is hall sensor,i don’t get it..
I know, makes no sense, but that is the actual BMW factory wiring diagram.
These are the diagrams for the Bosch ECU. These would make more sense. H is a 12v feed by the way.
I don’t know what the story is with the sensors for the Siemens control unit as i’ve never had anything to do with them. (may not have been an option in my country). The Bosch ECU sensors are definitely hall and VR. Might be easier to get new sensors.
A quick search shows you’re not the first to have issues with siemens sensors. I would swap them for later hall sensors in both.
somewhere i read it that…i try to connect like hall and i see
i end up to found 2 bosch sensors to fire it up
Ok so the first diagram you showed and the MS 40.1 DME is actually unique to the m50b20 Both the sensors in the diagram cant be used they are a weird high frequency job that no after market ecu will recognize. The m52 also has this same sensor on the cam only. The other versions of m50 are as follows: M50b25 non (NV) has VR sensors on both crank and cam. M50b25TU (single vanos) has standard Hall type on the cam and VR on the crank both can be used no problam. The m52 has the weird high Hz on the cam as mentioned and standard hall on the crank. M52TU/m54 (duel vanos) has hall on both cams and the crank. As far as I know all the sensors can be interchanged. Your best option is to swap out both the sensors from some of the other engines. You will need a hall for the cam as the the internal pickup will not work well with VR sensor. I like to use the intake one from the M54. For the crank you can use VR or HALL what ever you prefer so m52 if you want hall or m50B25 if you want VR both will drop straight in.
On the BMW E36/46 models from the early to mid 90s onwards and other models in the same era, there is 2 different ecus used, Bosch and Siemens.
Bosch is generally using VR sensors on the crank pickup and the Siemens ecu uses a Hall type crank pickup.
We always check this info first or on import/used engines we try and identify the crank sensor before supplying a aftermarket ecu or to give advise/support.