The BigMotronicPnP BMW M52 engine (originally Siemens DME MS41.0)
Currently the supported method involves: HALL replacement camshaft sensor: BMW 12 14 1 438 081 - Hall Effect Falling Edge. Pinout (from 1993 BMW .. .pdf document page#106 (m50 vanos)
The M52 (frequency output) factory camshaft sensor MUST be replaced with a normal digital output / open collector / open drain (that pulls to GND as 99.5% of CAM-sensors used in engines)
In the mean time I´ll be supplying VEMS PDF wiring info.
88pin motronic wiring information
http://www.vems.hu/files/M50Turbo/VEMS_Non_Vanos_M50_ETM_Guide.pdf
Here is crank and cam captures for BMW M52 engine single vanos.
Can this cam sensor be made to work?
The ignition signal is number 1 cylinder.
Frequency changes during the toothed section and then go back to lower frequency when the tooth has passed
- even if it's implemented in firmware (fw modification + related config), some signal conditioning (LM1815 or similar) is needed, so Marcell made some prototype (actually with 3 different methods, 1 dropped and 2 good: both with their advantages) to convert signal to HALL type. (for original M52 sensor => v3, or possibly other ECU like Motec).
- assumed 1400 Hz and 2500 Hz signals (but also tested with 1700 Hz and 2100 Hz to be sure)... What are the actual signal freq ? Also, how does it look at the transition ? (sometimes glitch, or changes freq at zero crossing ?)
- This info would be nice for testing (the more realistic the better: for v3 trigger testing we play trigger waves captured from real engine, from recorded triggerlog, and also generated signal).
- Because no scopeshot received, and swapping the cam-HALL sensor is the preferred choice anyway, the freq => HALL circuit has NOT been deployed
Currently the supported method (also see MembersPage/JasonVoytilla/BMW/Sensors
) : HALL replacement sensor: BMW 12 14 1 438 081 - Hall Effect Falling Edge. Pinout (from 1993 BMW .. .pdf document page#106 (m50 vanos)
- 1) power
- 2) signal
- 3) ground
Note: m52 page#98 has camshaft sensor middle (pin#2) going to mot88/pin64
That matches Gunnar's xls for camshaft (just forgot to mention HALL). So
- EC36/13 camHALL input= BMW88/pin64 (middle pin on the replacement HALL sensor connector)
- EC36/26 GND BMW88/pin43
- BMW88/pin65 HALL sensor + supply
- originally 12V was mentioned, but actually depends on the replacement cam-HALL sensor. 5V might be a better choice depending on the sensor.
Unrelated:
- BMW88/pin54 +12V from DME relay (powered by the main relay, actuated by BMW88/73=EC36/16)
- this is not related to cam-HALL (unfortunately was originally somehow listed in a way that caused confusion)
M52 PnP main relay buzzing issues
Seen on two ECUs now.
ECU Serial numbers are 17304 and 14951.
I´m going to have my customers send them back for fixing.
Easiest solution would be that VEMS buys as 323i or 328i and plugs in and tests it? A car like that should be easy to come by in Hungary for little to now money?
This has not happened on the other M52 PnP ECUs I´ve bought before.
In November we tested 2 M52 PnP ECUs (random), supplying +12V through the main relay in all possible combinations (ECU powered up, not powered up, ...), and could not reproduce the buzzing.
Can you measure an misbehaving ECU with DVM diode mode; Between main relay output pin (red probe) and testing other outputs (black probe)
- ECU supply pin
- flyback pin
side experience, it happens if main relay which provide 12v feed for injectors and flyback pin is driven from p259 channel. valdas.