lawlence

On my most recent outing, I noticed that my front and rear brake pressure traces had some huge spikes on my AIM logger. I am using a Solo 2 DL plugged into the Option 3 connector on a 991.2 Cup.

None of the other data channels have this kind of noise. Interestingly enough, it was subsiding as the day went on but still spiking to the same levels, just at a lower frequency and typically only at the end of a braking zone (see screenshot 3). It was recording brake pressure correctly if I was actually on the brakes. I've checked the grounds on my ABS unit and they are solid, and this noise is not present in the Cosworth data.

I doubt there is anything mechanical actually going on as I don't feel anything through the pedal, and 10000psi would have probably ruptured the brake lines!




This was on a warmup lap so there were extra application of the brakes during the lap, but notice no spikes:



This was from the final session of the day. Much less noise but spikes were still present:

carbondan

Readings at the extreme upper or lower limits of sensors in general is a good indication the sensor is on its way out. Cheap replacement fortunately.
you can also try to reset the zero within the pi toolset.

lawlence

Only seeing those readings on the CAN stream to the AIM though. Cosworth data is normal.

And I think it's highly unlikely that sensors for both front and rear channels are on their way out at the same time?

carbondan

That'd be the best test - compare Pi data vs aim data. If the sensor was bad it should be mirrored in the Pi data as well.
Check the data rate and check the upper limits for the value in the aim software (been while since I messed with AIM on the huracan, don't remember specifics clearly). Given it didn't spike during a warmup lap, I wonder if you hit a predefined 'max' value and that sends it to the reported max value of 10,000. It's strange though because it's mostly happening as you're bleeding off the brakes - maybe a debounce setting you look for?
If there's a way to re-zero the sensor in aim that'd be a good idea.

lawlence

Yeah I am thinking this is an AIM problem. The dash is calibrated to a 3500psi max on those sensor channels, so it couldn't possibly be transmitting a higher value via CAN to the AIM. Could be interference in wiring possibly?