U0202 indicates that the Powertrain Control Module (PCM) has lost communication with the Door Control Module. This means the PCM cannot receive status or send commands to the door latch and lock actuators.
Internal failure of the door control module’s circuitry or voltage regulator prevents it from responding to PCM requests.
Loose pins, broken wires, or corrosion in the CAN‑bus wiring between the PCM and the door module can interrupt communication.
A bad ground strap or a blown fuse/relay supplying the door module can cause intermittent loss of communication.
Bent, dirty, or misaligned pins in the connector at either the PCM or the door module can break the network link.
Only after all wiring and module checks have been exhausted should a PCM internal fault be considered, which is uncommon.
Replacing the PCM is rarely the solution. Most U0202 cases are caused by the door module, wiring, or connectors. PCM replacement should be a last resort after all other possibilities are eliminated.
Clearing the code may temporarily turn off the warning light, but if the underlying communication fault remains, the code will return and the door functions will still be impaired.
The vehicle can usually be driven, but door lock/unlock functions may not work reliably, which can affect security and convenience.
A standard OBD‑II scan tool that can read manufacturer‑specific codes and monitor CAN‑bus data is sufficient for most diagnostics.