Do you mean the two pins should somehow be attached together ?
Yes, on the 1.7 models there's a plug inserted into this connector,
which shorts these terminals. As far as i know the ECU must be
"rebooted" by interrupting it's power supply in order to check the
presence of this short circuit and use the injection&ignition map
If this short circuit is missing, the 1.7 engine will run lean
(mainly at low ambient temperatures, resulting poor throttle response)
until the closed loop mixture control is enabled.
I'm very interested in any info about this, but I probably try to get additional info elsewhere as-well.
I'm a bit worried about shorting the wrong wires !
OK, no problem.
A bit odd, isn't it ?
I have to say, in this case it's probably not a bad idea to connect LED and the switch directly to the ECU.
I included an image of the pin-layout of the MP3.1, if you could tell me what you think is the flashing code pin and if you know the pin for the switch.
Yes, maybe the flashing function is not implemented in this type of ECU,
that would explain why pin#17 (the flashing code pin) is marked as N.C.
Ps.: I expected this would be the easy way to read the fault-codes, but maybe it is easier to connect the T1 straight to my serial connector on my pc (down-side is that I have to take my PC into the freezing garden).
On the 16V models much easier to perform this, because besides the "Alfa tester"
diagnostic connetor (T1) there's a dedicated connector for flashing code reading (T2).
This T2 connector is completely omitted from the 33 models with Motronic MP3.1
About the serial connection with PC: be careful, because RS-232 of the modern PC's
are often working with 5V TTL line voltage (but 3,3V versions also exists) and may not
tolerate the 12V car line voltage on the Rx pin. At the other hand the Tx pin voltage may
not enough to drive the ECU's Rx line.