EMB ERJ 170/175 First Officer reported the failure of MAU 2B in cruise. The Flight Crew made a precautionary landing at destination airport and the aircraft was towed to the gate.

Narrative

On flight from ZZZ1 to ZZZ; Aircraft X experienced an AVNX MAU (Master Avionics Unit) 2B failure approximately 250 miles from ZZZ. The aircraft was at FL310. Upon experiencing the failure; the Captain was the Pilot Flying and had me identify and cancel. I pulled out the QRH and went step by step through the procedure with the Captain. Upon completion of the checklist we determined that a [request for priority handling] was appropriate and to request Crash Fire Rescue. We notified dispatch; the Flight Attendants and the passengers of the situation. The failure of the MAU caused us to lose our inboard brakes; ground and terrain proximity warning and a number of other messages. Based on the loss of our inboard brakes and with an increased runway requirement we would need CFR on site. We also selected Runway XXR as winds were favorable and it was 10;006 ft. runway. This was adequate based on the QRH number assessment for landing. We ran the Landing Gear/ Brake Malfunction descent and landing checklist in accordance with the QRH. Upon landing we experienced decreased braking capability but sufficient enough to safely stop. While stopping I also had up the system page to additionally monitor brake temps. We safely landed without any deviations or damage. After clearing the runway; we were asked by ATC to quickly taxi across XXL. I told them we were unable and reminded the controller that we had to brakes that failed. I personally was not happy that the Controller lost situational awareness and asked us to do something that was potentially unsafe. He acknowledged and we waited for to clear XXL. Upon taxiing into the gate the aircraft got the Brake Overheat message. We once again identified and canceled and I read the QRH and we executed it. The Captain stopped the aircraft and we determined the best course of action was to have the aircraft tugged to the gate. We had Crash Fire Rescue Equipment inspect us multiple times upon landing to ensure there was no threat to our passengers or crews from the hot brakes. We subsequently were tugged into the gate and waited for maintenance to respond. Upon arrival to the gate; Maintenance wanted to have the aircraft shutdown and brought back on line to see if the fault would clear. At this point; I was frustrated and felt like a better assessment of the reliability of our systems needed to occur after the failure in flight. We already had MEL XX-XX-XX-X for the FADEC (Full Authority Digital Electronic Control) that required an alternate ignition operations procedure on it. In response to this; I could tell that stress had set in and I made the decision not to continue flying for the rest of the day. After flying in the military for XX years; I call it the rule of three. When three things happen bad in the aircraft.... It's time for me to do a personal assessment of where I am at IAW (in accordance with) the personal assessment checklist. I also started to talk myself into continuing for the day which is a dangerous attitude to have. Upon recognizing that the event caused more stress than everyday operation; I informed the Duty Pilot and scheduling that I was not going to continue. I also talked to the Chief Pilot. I am glad I did this. Looking back at yesterdays events; we had a lot of additional complexities that we do not encounter on a normal day. These system failures were not our fault; but the QRH was well written enough to get us safely on the ground. We had good CRM throughout the [incidents]. I think our crew did a phenomenal job identifying and mitigating threats both in and after the flight; and that is why I am sharing this. I am also happy that there were both union and company personnel who supported my decision based on my self assessment. This is a positive cultural aspect that I would like to highlight. [I would suggest to] continue to train emergency and QRH usage. Continue to ask crews to do self assessments... we are not all built the same way. Learn from these failures and validate QRH procedures.