U0022 indicates that the vehicle's low‑speed CAN communication bus is detecting a low voltage or signal integrity problem. The bus is used for many control modules to exchange data at low speed, and this code signals that one or more modules are not communicating properly.
Damaged, corroded, or loose wires and connectors on the low‑speed CAN bus can interrupt signal transmission.
A poor ground on the CAN bus or on a module can cause low voltage on the bus lines.
A malfunctioning control module such as the Body Control Module, instrument cluster, or HVAC controller can stop transmitting messages.
Improper termination resistors or supply voltage problems can degrade bus signal integrity.
Failure of the PCM’s CAN transceiver is rare but can occur if the module is damaged.
In most cases the PCM is not the cause; the code is usually due to wiring, connector, or another module issue.
Yes, insufficient voltage can affect CAN bus operation, so the battery and charging system should be tested.
No widespread recall exists; the issue is typically resolved by repairing wiring or a faulty module.
A standard OBD‑II scanner can read the code, but a scan tool that displays live CAN bus activity helps pinpoint the faulty node.