U1900 FORD, MERCURY: CAN COMMUNICATION BUS FAULT.
POST UPDATED IN June, 2023
U1900 FORD, MERCURY: CAN COMMUNICATION BUS FAULT.
The OBDII DTC U1900 is a manufacturer-specific code that is set when the Powertrain Control Module (PCM) finds a breakdown to communicate with itself, the ABS Control Module, the instrument cluster, and the trailer brake controller when the car is on, and it is also in drive position. Although the CAN (Control Area Network) bus connects all the control modules, the U1900 code specifically refers to communication failures in the circuits connecting the PCM to the ABS Control Module and the instrument cluster.
In summary, the CAN bus is a system that allows high-speed communication of all the vehicle control modules. As a result, the information on operating conditions is shared through a very complex wiring system.
The PCM, instrument cluster, and ABS Control Module are connected to two specific CAN bus circuits, 1908 and 1909, they do not accept faults like the rest of the CAN. Therefore, if there are intermittent connections or out-of-range values, they will be interpreted as faults in the communication, so the code 1900 OBD2 will be set.
Reasons for setting the U1900 OBDII fault code:
Steps to troubleshoot the U1900 OBD2 diagnostic code: