After plugging in the ECU the first time (with INJ and coils unplugged), I uploaded using the Audi Tool under Tools > Firmware).
I noticed that everything was working correctly except for the MAP sensor, which upon ECU startup (ignition) would start to count up (kpa) until approx 328.
After quickly speaking with Marcell, he suggested to check the MAP and see if the resistor is not set properly and that it could be removed and bridged (0 ohm) as it's not really needed.
first pass with the soldering iron I went over every solder point on the back side and connection to main PCB, no change.
I then proceeded to remove the resistor and connected solder pads on MAP with solder instead, issue also still remained.
I then took measurements at PCB connectors with DVM while ECU was connected to the car.
Between pins 3 (5v) and 2 (GND) = 4.93V
Between pins 2 (GND) and 1 (V out) = it was also a falling voltage from when ECU is turned on around approx 1.x V settling to ~0.38 V.
Connect a resistor (1kOhm would be awesome, but 2k4 or 2k7 would also) between
- MAP input (pin1) and GND (pin2)
- measure voltage and see MAP gauge
Remove that resistor, and than connect it between:
- MAP input (pin1) and +5V (pin3)
No need to solder, this can be done quickly by touching it (throughole resistor is preferred).
But make sure not to short pin2 to pin3 (GND to +5V).
From the result we would see which side is the problem
- if MAP reading changes when tweaking with the resistor, than MAP sensor (I find that more likely). In that case the 3 pins of the SMD MAP sensor should be checked.
- if MAP reading does NOT change when tweaking with the resistor => mainboard (which is not very complex either, the MAP trace contains a resistor). Check the SMD resistor on the mainboard right next to pin1 of the sensor.
- Ended up being the MAP sensor itself (pads to the MAP board I suppose. Needed to disassemble and re-solder all pads on MAP itself to fix and reassemble.