Subpage of MembersPage/MarcelBMW_M50B25_Turbo
For Vanos, see: MembersPage/MarcelBMW_M50B25_Turbo/Wiring/PfetOutputs
For ground, see MembersPage/MarcelBMW_M50B25_Turbo/GroundChecks (important, because several symptoms indicate grounding problems)
v3/15130 v3=15130 gut replacement => v3=20026
Apparently in 2019 (oid15399 repair/gut replacement) device has been replaced with brand new electronics, but if problem that caused damage in the first place is not fixed, it is likely to be an infinite cycle.
Install is started with a wiring list (must always be present, regardless if universal harness or made from scratch).
outputs
- For Vanos, see: MembersPage/MarcelBMW_M50B25_Turbo/Wiring/PfetOutputs
- '''ignch2 EC36/34 fuelpump relay-
- PLEASE CHANGE to EC36/9 or EC36/17 injout to drive fuelpump relay (relocate boost or idle solenoid to stepper out if needed)
- injector shared + (flyback EC36/23)
- grounds, see MembersPage/MarcelBMW_M50B25_Turbo/GroundChecks
- inputs
- the relay-box would also be interesting, maybe something weird ?
- (although rare, but if ECU is powered indirectly, through a solenoid, that could cause weirdness when running)
Diagnostics is not feasible before the install is started this way, with wiring list
- It is impossible to do the essential verification measurements without them anyway.
Grounds: list those connected, and do the measurement with breaklight as a load
- With ECU disconnected, please use a 2A (25W) brake-light bulb to flow current and measure voltage drop (should be <30mV)
- VEMS ECU has extremely strong injector and ignition outputs (10A capable) wether the engine is running or not.
- If the ECU cannot activate some of those outputs while engine is running, it is almost always related to wiring (eg. grounding) problem.
Outputs - please complete: list ALL connected outputs
Please note that there are several indications that this install is severely messed up and should be started to be documented as requested - all outputs, really !
- Stepper - A : Vanos (solenoid resistance: ... Ohm, - side)
- was ordered with 4 PFETs, it seems nonsense and invalid to use stepper output to drive vanos !
- Why don't you use PFET outputs ?
- Please test p259 outputs (with DVM, as 5V base, activate from VemsTune)
- ignch2 : fuelpump (relay, - side)
- ...
- is it possible to see the measurement notes related to ground and flyback measurements ?
- or do the measurements now and take notes ?
- Ohm measurements, with ECU disconnected. For ground wires, mV measurement would be superior, with 2A flowing through (eg. break-light bulb or 25W bulb would be awesome, <30mV drop over any wire + connector pin)
https://www.bilder-upload.eu/bild-4c8044-1579209910.jpg.html
Measurements i have already done on all Grounds and the + connections.
Grounds = exact same everywhere
Measured from pin to chassis and from pin to pin (ohm of course)
Dont forget please that every output works if the Engine dont run.
When the Engine runs it does not send Ground to the relay for fan and fuelpump.
Changed the output already and problem still exists.
- VEMS ECU has extremely strong injector and ignition outputs (10A capable) wether the engine is running or not.
- If the ECU cannot activate some of those outputs while engine is running, it is almost always related to wiring (eg. grounding) problem.
Measuring woth lightbulbs and special Measuretools not easy in my garage because i only have a multimeter and 1 battery.
- yes, but it is likely to help (hopefully that will give some motivation...)
- On the countrary, sending the ECU anywhere in case of similar symptoms is unlikely to help, because with such symptoms the harness must be verified first, really.
Although pic are no replacement for wiring list, some more could be uploaded, see FileArea
Original ECU specs v3/15130 (please check if v3/20026 is same):
ECU VEMS V3
- primary_trigger: EC36/27 VR
- secondary_trigger: HALL
- ignition driver: 2+6
- Hi-side PFET outputs: 4
- EGT input: 1
- Knock input channels: 2
- Flyback: HighZ-only 30V flyback
- MAP connection: 300 kPa simplenipple
- mounting-style: flanged case
- Special requests: no
- withSDcard: no
- ETC BridgeOutput_Interface: 0
- LCD connection: no
- 1-wire interface: no