This code indicates that a control module on the vehicle's high-speed CAN bus (often the "C" bus) has stopped communicating with the rest of the network. It means data is not being exchanged between one module and the network, not necessarily that the module is dead.
Open, short to ground/power, or high-resistance connection on the twisted-pair CAN lines is the most common cause of a single module dropping off the bus.
A module that is shorting the CAN high/low lines internally can take itself (and sometimes the whole bus) offline. Isolation testing is required before condemning it.
A missing fuse, relay, ground, or corroded power feed will make a module appear "off" to the network even though the bus wiring is intact.
Damaged terminating resistors, a poorly installed aftermarket module, or a splice/corrosion issue can disrupt communication on the CAN-C segment.
Rare. The engine computer's CAN transceiver would have to fail without other obvious damage; this should only be considered after the bus and all other modules are proven good.
No. In most cases this code is caused by a wiring, connector, power/ground, or peripheral module issue on the CAN-C bus. Replacing the PCM is rarely the correct first step and should only be done after the bus and all other modules are proven good.
It depends on which module is affected. If the code involves a powertrain or safety-related module, drivability or safety features may be impaired. If it is a convenience module, the vehicle may still be drivable, but diagnosis should not be delayed.
Because modules share the same bus, one lost node or one wiring fault can generate communication codes across several modules. The key is finding which module is actually offline, not replacing parts for every code.
Low voltage or voltage spikes can cause modules to drop off the bus temporarily, but U0075 usually points to a persistent communication fault. Always verify charging voltage, but do not assume the charging system is the root cause without bus testing.