Related to BMW M52 MembersPage/BmwMFiftyTwo
Measure HALL trigger supply voltage
Related to:
- mot88/54
- mot88/65
- Serialnr
- Vemslog captured with VemsTune during the cranking attempt could reveal something (eg. it would be awesome if only some configuration adjustment would be needed).
However, for trigger problems more measurements are almost always needed also:
- Measuring triggers, DC and AC voltage
- OscilloScope the trigger signal might be necessary
- InputTrigger/TriggerLog
- this might reveal that signal is missing from only primary or only secondary HALL sensor (or both).
Preferrably create custom page for the project (but editing this page to provide information is temporarily OK, possible to organize later, just define some project nickname ).
Old harness
We have a 6cyl BMW harness with 4 connectors of female 3-pin injector (AMP)
TPS
- mot88/42 (TPS GND or shield ???)
- mot88/12 TPS signal (EC36/1)
- mot88/44 +5V for TPS
primtrig HALL: Crank sensor
- mot88/48 Crank sensor +5V
- mot88/83 Crank sensor signal (EC36/27)
- mot88/40 Crank sensor GND (EC36/26)
sectrig HALL: CAM sensor
- mot88/65 CAM sensor 12V ( diode to ->|- mot88/54 might be undesirable ??)
- mot88/64 CAM sensor signal HALL EC36/13
- mot88/43 GND
Idle Valve
- mot88/27 Idle (INJ-H with low voltage flyback)
- mot88/54 DME relay out 12V (this is NOT camsensor 12V as in the errenous doc)
- measured on the floor, ripped out from car
- Dave: pin54 connected to idle middle pin could be correct. mot88/54 comes from DME relay back to ECU (so DME relay switched +12V) also goes to middle
- mot88/53 Idle (INJ-G with low voltage flyback)
https://photos.app.goo.gl/vT76gkVCSKQoLUZS8
Maybe this is from some other harness, not M52 ?
- maybe M60 (didn't check just blind guessing)
- apparently perfectly matches the "M52" harness in the car with ECU Siemens DME MS41.0 (5WK9 0321)
M52 Test bench
Planned: M52 harness from E39 manual transmission
Acquiring a harness from E39 for more tests.
Conclusion:
- got mislead by information (from previous install from a customer - successful VEMS install, but with EC36) "BMW uses 12V HALL sensor supply"
- it seems we (the ECU) must simply supply 5V for TPS and the HALL sensors: pins 44,48,65 and leave pin54 open
- (instead of the traditional +5V), +12V supply (even through a diode, to prevent unintentionally powering the ECU back from mot88/54) for HALL sensors might NOT be a good idea in this setup.
- of course, activating the DME relay (mot88/73 to GND) still needed. but even activating that (with ignition on) does not provide + supply for HALL sensors (verified on real car in factory harness+setup). So HALL supply becomes simpler actually.