X20 pinout help

[PiercedE30]

Ok, I am in the middle of making my X20 -> C101 adapter. I have been going through the ETM and ended up looking through all 470 some odd pages and was able to find all but two pins. Pin 21 (which is green) and pin 22 (which is green/white). I am using addissimo's pinout in helping aid my progress while double checking it with my harness. According to his chart those pins should be ignition switch (pin 21) and o2 sensor, heater relay (pin 22). Only problem is that I can't find it in the ETM. If someone would could either a) confirm this or b) tell me the etm page number that these pins are on, it would be greatly appreciated.

The harness is for a non-vanos M50 from a 04/1992 automatic E34.

Jon

[ian332isport]

X20 Pin 21 on the 92 E34 M50 harness is usually connected to the ignition switch (terminal15). This provides ignition switched power to the ignition coils and pin 56 of the DME. When connecting to an E30, this supply is usually found on pin 7 f the C101 (also green).

X20 Pin 22 on the 92 E34 M50 harness is also a 12v feed from the ignition switch. On the E34 it provides power to pin 16 of the diagnostic socket. I guess this is not strictly needed on an E30 conversion, but if you do wish to connect it, it usually connects to pin 6 of the C101 which was the 12v feed to the O2 sensor heater relay (E34 heater relay gets it's power from else where).

Ian.

[PiercedE30]

Cool. Thanks Ian.
So pin 21 is needed, pin 22....not so much.
Thanks for the help.

Jon

[ian332isport]

So pin 21 is needed, pin 22....not so much.

Hi Jon,

Pin 21 is deffo needed. Pin 22 can be seen as optional. I would personally connect it as it may mess with any diagnostic equipment that you have connected at a later date, but as far as getting the engine running, it's not needed.

Ian.

[PiercedE30]

Yea, I am going to connect pin 22 to pin 6 on the c101.
Now, on the X20 at pins 16 and 17, I am not sure I need them or if they do something. According to the ETM, pin 16 is the RXD side and pin 17 is the TXD side of the datalink connector. I know it lets you read info about the srs sytem and the abs system with a code reader (I assume). So, are they neccessarry to connect be able to use a code reader once it is up and what should I do with them?

Jon

Oh, and thanks for the help Ian.

[ian332isport]

According to the ETM, pin 16 is the RXD side and pin 17 is the TXD side of the datalink connector. I know it lets you read info about the srs sytem and the abs system with a code reader (I assume). So, are they neccessarry to connect be able to use a code reader once it is up and what should I do with them?

You don't really need the TXD & RXD signals. As you say, this is for coding different modules on the E34 that you don't have on the E30.

My engine is post 95, so I have the EWS immobilizer system. I did add the TXD & RXD wires just incase it ever needed to be aligned with the DME.

The only diagnostic wire you do need to connect is the one from Diagnostic plug pin 7 for the service reset.

Ian.

[PiercedE30]

Now, on the pin 2 of the C101 plug is the oil level (static). But on the X20 plug I have pin 1 as the dynamic oil level sensor and pin 23 as the oil pressure. Is the static level on pin 2 of the X20? Or is it elsewhere?

Jon

[ian332isport]

Now, on the pin 2 of the C101 plug is the oil level (static). But on the X20 plug I have pin 1 as the dynamic oil level sensor and pin 23 as the oil pressure. Is the static level on pin 2 of the X20? Or is it elsewhere?

Jon

I've got X20 pin 1 as static and X20 pin 2 as dynamic. X20 pin 1 to C101 pin 2 and X20 pin 2 to C101 pin 10.

Ian.

[PiercedE30]

Ok, that makes sense. I see thwt the dynamic level has the resistor on it and the static one doesn't. Ok, cool.

Jon

[PiercedE30]

Ok, here is my chart.....give some advice on it if you can.

C101 -- X20 -- Function
1 ---- 25 -- Alternator Charging
2 ---- 1 -- Oil Level (Static)
3
4 ---- 12 -- Coolant Temp Sensor (Gauge)
5 ---- 23 -- Oil Pressure Switch
6 ---- 22 -- 12V Feed for Diagnostic Plug
7 ---- 21 -- Ignition (Switched)
8 ---- 24 -- Fuel Economy
9 ---- 20 -- Engine Speed (Tach)
10 ---- 2 -- Oil Level (Static)
11 ---- 7 -- SI Reset
12 ---- 8 -- CEL
13 ---- 13 -- Fuel Pump Relay
14 ---- 14 -- Speed Signal
15 ---- 15 -- Starter (Unloader Relay)
16 ---- 19 -- Diagnostic Plug
17
18 ---- 18 -- Voltage During Startup
19
20 ---- 3 -- ABS Control

This is for a 1990 E30 to a 1992 E34 with NV M50.

[e30_kid89]

looks about right so far dude.....hope u dont get bombarded with the kinds of difficulties i've run into...

[PiercedE30]

i'm just trying to get this done so that when taxes come i can finish this beast.