OBD-II code U0213 indicates that the vehicle's primary communication network (CAN bus) has lost the ability to exchange data with the mirror control module. This typically means the module is not responding to requests from other control units, often due to an electrical or communication fault.
The module itself may have an internal failure, such as a power supply issue, corrupted firmware, or a hardware defect, preventing it from communicating on the CAN bus.
Damaged, corroded, or loose wiring or connectors in the CAN bus circuit can disrupt communication. This includes open circuits, shorts to ground or power, or high resistance in the wiring.
A lack of power or ground to the module due to a blown fuse, faulty relay, or poor connection can prevent it from communicating on the network.
Problems with the CAN bus itself, such as a short to ground or power, an open circuit, or high resistance in the bus wiring, can disrupt communication with multiple modules, including the mirror control module.
A weak or corroded ground connection can cause the module to malfunction or fail to communicate properly on the CAN bus.
While uncommon, a failure in the PCM or another module acting as a gateway for the CAN bus could theoretically disrupt communication with the mirror control module. This is a last-resort cause after all others are ruled out.
While low voltage can sometimes cause communication issues, U0213 is typically not directly caused by a weak battery or alternator. However, if the vehicle’s electrical system is unstable, it may contribute to intermittent communication faults.
Yes, this code does not affect the vehicle’s drivability or safety. However, you may lose functionality of mirror-related features, which could be inconvenient or reduce visibility in certain conditions.
Replacing the PCM is rarely the solution for U0213. The issue is almost always related to the mirror control module itself, its wiring, or the CAN bus network. Only consider PCM replacement after all other causes have been thoroughly ruled out.
Intermittent communication issues can cause the code to set even if the mirrors appear to function normally. The module may still respond to direct commands but fail to communicate consistently on the CAN bus.