Cummins ISB CM850 (2003-06) Fault Code: 287 PID: 91 SPN: 91 FMI: 19 SAE J1939 Multiplexing Accelerator Pedal or Lever Sensor System Error – Received Network Data Error. The OEM vehicle electronic control unit (VECU) detected a fault with its accelerator pedal.

This fault can occur when the OEM VECU detects an error on the accelerator and or idle validation switch. The ECM has been set up properly (components enabled and OEM VECU source addressed correctly) to receive multiplexed information for the idle validation switch states and accelerator position over the J1939 datalink from an OEM VECU, and the OEM VECU is transmitting the message for that component.

The three types of errors that can occur for this fault are:

1)When the accelerator is depressed and the OEM VECU reads accelerator position as greater than 0%, but the idle validation switch indicates it is in the idle position. This fault status is transmitted to the Cummins ECM on the J1939 datalink, which causes this fault to occur in the Cummins ECM.
2)When the accelerator is released and the OEM VECU reads accelerator position as 0%, but the idle validation switch indicates it is not in the idle position. This fault status is transmitted to the Cummins ECM on the J1939 datalink, which causes this fault to occur in the Cummins ECM.
3)The OEM VECU determines that the accelerator signal line is shorted high or shorted low.

NOTE: It is still possible to get a Fault Code 285 or 286 if there is an incorrect setup in the OEM VECU or Cummins ECM, for other components, or the accelerator and idle validation switch, or if the datalink is damaged. OEM configurations must multiplex the accelerator and idle validation switch inputs together to allow the use of the J1939 multiplexing and limp home feature for these components. INSITE? can be used to monitor multiplexed components.

Possible repairs:

1)Replace the OEM harness.