bmwkraftur.is

This is not a fully comprehensive post but acts as a starting guide for whoever wants to wire a VEMS to a Motronic 1.3 loom. Or at least the way I do it.

First is a picture of the VEMS pinout

I will call them EC36 and EC18



I will do them in the order of VEMS pin numbers and start with the 36 pin connector

1. TPS - This is new wiring for a variable TPS sensor, can be done with the stock wiring if you cut and move the wires in the TPS connector.

2. IAT >> 44 , by cutting the AFM loom you can retreave the GY/VI wire and use that instead of laying down new wires, the ground part of the sensor can be connected to 26 which is an analog sensor ground wire GY/BU which would need to be connected to the grounds at the ecu.

3. These can be used to power relays and such, no use for now
4. Same as #3.
5. Ground - Can be wired to any of 19,14,2 or 24 on the motronic side
6. Wired either #4 or #22 , doesn´t matter can be inverted in software
7. >> 16 BR/WT - Injector wire for 1,3 and 5
8. >> new wiring to injector 3
9. >> new wiring to injector 5
10. Empty
11. Empty
12. Empty
13. Empty unless you can be bothered with a cam sensor fitting, no use unless you have plenty of emissions testing time and a gas analyzer around.
14. >> 45 BR/RD - Coolant temp
15. >> 3 BR/GN - Fuel pump relay
16. >> 36 BR - Main relay
17. Same as #6
18. >> 17 Injector 6
19. New injector wiring for number 2
20. New injector wiring for number 4
21. Ground - Can be wired to any of 19,14,2 or 24 on the motronic side
22. Ground - Can be wired to any of 19,14,2 or 24 on the motronic side
23. >> 37 - Main relay 12v return
24. Empty
25. >> 27 GN - Switched 12v from ignition switch
26. >> Ground - Can be wired to any of 19,14,2 or 24 on the motronic side
27. >> 47 Crank sensor signal Black
28. Empty
29. TPS supply to variable TPS
30. Empty
31. Empty
32. Ground - Can be wired to any of 19,14,2 or 24 on the motronic side
33. >> 1 , Ignition coil
34. >> Empty
35. >> Empty
36. >> Empty

Grounds : There are 4 grounds in the Motronic loom but 5 ground connections on the VEMS , the 4 must be soldered together and then split into 5 and then into the VEMS, like so



TPS :
For a M50 TPS as an example you can use your existing wiring by cutting and resoldering or de pinning the 3pin connector.

The M50 TPS is so
#1. Ground
#2. Signal
#3. 5v

#1 can be wired to what was #2 (Brown)
#2 can be wired to Brown/Blue and then at the ecu connected to signal input (EC36-1)
#3 can be wired to TPS supply (EC36-29)

You then need to configure the TPS
VEMStune - Tools - TPS Calibration Wizard.


This will save on new wiring and use most of what is already there. For further usage there will be 2 available wires remaining in the AFM loom portion as well.

Charcoal canister wiring can be used for boost solenoid use : this is number 5 in the motronic loom , Brown wire

Injector wiring :

I like to cut a hole in the back of the injector cover and put all the wires from the injectors out of there into a 4 pin connector, then from there to the ecu. The wires for inj 1 and 6 are using the original wires so only 4 need to go from there or you can put them down where the other injector connector is. I like to have a connector as that allows the injector cover to be removed like stock.

Rest of any wiring information can be found in
http://www.vems.hu/wiki/index.php?page= ... FUserGuide

Wideband sensor :

Pretty straight forward from the first picture ,
you can take 12v from the O2 relay and have the ecu power that relay using one of the P259 channels or simply tap into any of the RED/WHITE wires for power to the wideband sensor (main relay turns these on).

After the sensor is wired it must be calibrated from Vemstune
Tools - WBO2 Calibration (new)



EC18 connector

4. >> 6 , Tachometer.
8. >> 29 , Speed signal from dash,
17. >> Serial ground

The M30 and M20 looms are the same as the ecu is the same.
Any questions just ask.