Cummins ISX CM870 (2003-06) Fault Code: 285 PID: S231 SPN: 639 FMI: 9/9 The ECM expected information from a multiplexed device but did not receive it soon enough or did not receive it at all.

When this fault code is active, some multiplexed devices can possibly not function as desired.

Possible causes:

1)When the ECM is set up properly (components enabled and OEM VECU source addressed correctly) to receive information from an OEM VECU, but the OEM VECU is actually transmitting a message that says that component is not available for multiplexing. This can be caused when a multiplexed component is enabled in the ECM, but the OEM VECU source address of the VECU transmitting the component message is incorrect in the Cummins? ECM, or the OEM VECU is not set up to transmit the multiplexed component message.
2)This fault can also be caused by a damaged J1939 data link connection between the OEM VECU and Cummins? ECM, a damaged connection between the component and the OEM VECU, damaged OEM VECU or damaged Cummins? ECM. It can become necessary to contact the OEM for proper multiplexing configuration.

For intermittent power supply and datalink communication issues with Aftertreatment Components, it is highly recommended that the OEM Power Distribution Center fuses and relays be thoroughly checked for loose, missing or intermittent connections.

Possible repair:

1)Repair or replace the OEM harness.
2)Replace the termination resistors.
3)Replace the SAE J1939 backbone.