Pulling ECU Code - final step - 348TB

Hi All

I have worked through the winter to get to the final step of pulling ECU code - I would like to ask whether someone can give a little hand to get this done?

Since I have a European 348TB there were no ECL lights and I don't have a switch.
During the winter I decided to get things prepared to sort out the (hopefully) last problems and this is what I did:
- installed new exhaust ECUs
- did the Gold Contact Kit replacement work including new contact blocks at the main ECUs
- put in ECU lights in the dash-board

After many hours work (as well as some reconditioning of the center console due to the sticky-problem and plutting in some LEDs instead of bulbs) I finally started the car again and took her out for a half-hour drive.

- before the work the car was virtually undriveable (cyclinder row cutting out at above 3'000 rpm quite regularly) and idled very poorly.
- today the idle was very clean while I let the ECUs re-learn
- during the half hour drive I carefully checked the cars handling, breaking and performance under different conditions (remembering I hadn't driven for over 6 months...).
- After 10..15 minutes I became more confident and found that the acceleration was good and idling after hard breaking also good (before it would tend to want to cut-out and had to be 'caught' by 'blipping' the throttle).
- Therefore the intemediate results were very promising.
- After about 20 minutes the "Check Engine 1/4" light went on. It would intemittently go out again but spend most of the rest of the time on. Sometime the idle fell a bit low at crossings (down to 750..800 rpm for a short time before picking up to 1'000rpm)
- Therefore, although things are generally much better, the ECU in the one side is obviously detecting something that is not quite right.


This means that I probably have a couple of CEL codes to be pulled. I found a good description of how to do it and how to read the results: http://www.my348.com/

Still I am missing the switch and saw that presently they are not stocked at the suppliers, although I thought that I might order them anyway. But, during the ECU connector work I took a good look at the cables and also studied the electrical diagrams (I needed to because I actually had a short circuit when rewiring...!) and the switch contact has three pins. The middle pin is ground. This means that, to pull the codes, one has to probably connect one of the other pins to ground.

Is there anyone who has this cable/switch and can measure which contacts are shorted together when the switch is pressed? This would allow me to finally pull the codes!!!


I am also wondering about the way that the Motronic 2.7 works with the connector. I understand that it can be connected to a tester which will display the state of various measuremenst etc. Does anyone have any information about how this works? I suspect that it is a serial interface and so maybe it wouldn't be that difficult to connect it to a processor that reads the infomation (and the codes) and displays them in a useful manner.

I saw someone doing this with a 'standard' Japanese car and could connect a small adapter to the plug and display the details on an iPhone over a BlueTooth connection - it required a small App to be loaded to the iPhone. If I could work out how to communicate I would even like to have a go at getting something running in this fashion (the electronics part is what I can do if I can get a little information about how the communication actually operates - any one who already has some knowledge???).

Regards

Mark

 

Hi

I managed to work it out by carefully testing the wires to see whether they were inputs or outputs (connected them to the middle - ground- pin through a resistor of 1.3k and measured the voltage drop). They proved both to be inputs and while measuring one of them this already triggered the diagnostic mode.

The input which I used is the one with grey/red wire - for clarity (possibly they don't all have the same coloring) I took a photo. The two inputs to connected together are shown by the resistor - I actually used this resistor as a switch because it doesn't need a very low impedence to switch the input

And I could pull the codes - the values made sense - and could also reset them.

I'll look around to see whether there are any discussions of the (intermittent) O2 sensor error that I read or else may start another thread about it.

Regards

Mark
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