viewtopic.php?f=15&t=52077
free5ty1e wrote: Oh, snap. You actually have an FCD wired directly into an ECU patch harness - that's nice! That's the way to make a truly plug-and-play FCD, although thats quite a bit more parts and labor involved.
I've never seen one like this before, but I'd imagine it's all wired in to the ECU as it should be if VRG3 made it. Hmm... that'll make it tougher to troubleshoot as well. You'll have to find the ECU pin for the pressure sensor and verify that there is at least a signal going to it with the ignition on. Beyond this, my troubleshooting steps may be of help if you can identify which wire is which on the FCD. May require examining his schematic and the FCD a couple times - trace signals from the chip to the wires and you should be able to figure it out.
If you are able to get on boost, I'm imagining that the chip is still good; the symptom of a bad chip is typically the car cutting power as as soon as you start spooling up the turbo with any decent throttle. It may just be the voltage divider has drifted out of spec or degraded somewhat and is no longer keeping your voltage clamped below 3.9V.
If you are able to figure out which wire is which on the FCD, try wiring the +5v pin directly to the input pin and watch the output. If it goes above 3.9V then that's your problem; you'll need to replace resistors or adjust a potentiometer / knob if it has one and watch this output voltage until it is at 3.9V.
Hope this helps!