SAE J1939 Data Link Multiplexing
|Fault Code: 286
FMI: 13 (J1587),13 (J1939)
The ECM expected information from a multiplexed device but only received a portion of the necessary information.
At least one multiplexed device will not operate properly.
SAE J1939 Data Link Multiplexing Circuit
Inputs such as throttle pedals, switches, and sensors can be communicated to the ECM over the SAE J1939 data link. Messages sent from the vehicle electronic control units are received by the ECM and used for controlling the engine. Both the ECM and vehicle electronic control unit (VECU) must be properly configured so that each device’s information is transmitted by the vehicle electronic control unit and received by the ECM.
The ECM is bolted to the intake side of the engine between the air horn and the front of the engine. Refer to Section E for a detailed component location view. The SAE J1939 data link wiring and vehicle electronic control unit(s) vary by OEM options.
This fault occurs when the ECM is set up to receive information from several multiplexed switches from vehicle electronic control unit(s) and only receives some of the switches. It indicates the ECM is set up to receive too many switches or the vehicle electronic control unit(s) is setup to transmit too few switches.