U0072 indicates a short circuit has been detected on the vehicle's communication bus E (a CAN bus network). This means the data communication line is shorted to power, ground, or internally, preventing modules on that bus from communicating with each other.
The CAN bus wiring for Bus E is chafed, pinched, melted, or corroded, causing a short to power, ground, or between CAN high/low wires.
A defective ECU, sensor, or control module connected to Bus E has failed and is shorting the bus network.
Moisture, road salt, or debris has entered a connector, causing corrosion and a short circuit on the bus.
A wiring fault is feeding battery voltage onto the CAN bus communication line, triggering the short detection.
A wiring fault is grounding the CAN bus communication line incorrectly.
In very rare cases, the network gateway or main processor within the PCM could be defective, but this is an uncommon cause compared to wiring or module faults.
No. The PCM/ECM is rarely the cause of this code. In the vast majority of cases, the problem is wiring damage or a faulty individual module on that bus. Replacing the PCM is an unnecessary expense that rarely fixes U0072.
Driving is not recommended. The shorted bus affects multiple vehicle systems including safety systems like ABS and airbags. The vehicle may experience reduced functionality, fail to start, or behave unpredictably.
Modern vehicles use multiple CAN (Controller Area Network) buses to separate different systems. Bus E may carry communication for a specific group of modules (such as body controls, chassis, or powertrain). Having separate buses improves diagnostics and reduces traffic on any single network.
No. Clearing the code without repairing the underlying short will cause it to return immediately. The short circuit is a hardware problem that must be physically repaired.