ISB/ISBe Series Engines – FAULT CODE 286

SAE J1939 Multiplexin Configuration Error – Out of Calibration


Overview

CODE REASON EFFECT
Fault Code: 286
PID: S231
SPN: 639
FMI: 13
LAMP: Yellow
SRT: 

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.

J1939 Data Link Multiplexing Circuit
SMALL | MEDIUM | LARGE

Circuit Description

Normally, switches, accelerators, and other components are connected to the engine electronic control module (ECM) directly through individual wires. Multiplexing allows those same components to be hard wired to an original equipment manufacturer (OEM) vehicle electronic control unit (VECU) or transmission electronic control unit (ECU) in the cab. Then component values and states from components such as sensors, accelerators, and switches can be transmitted from the OEM VECU to the Cummins® ECM over the SAE J1939 data link.

Messages sent from OEM VECUs or Transmission ECUs are received by the Cummins® ECM and used for controlling the engine. The Cummins® ECM and OEM VECUs must be configured properly so that proper operation of the multiplexed components will occur.

Component Location

The J1939 data link wiring and VECU location varies by OEM. Refer to the OEM service manual.

Conditions for Running the Diagnostics

This diagnostic runs continuously when the keyswitch is in the ON position.

Conditions for Setting the Fault Codes

The ECM receives an invalid J1939 message from a multiplexed device for more than 1 second.

Action Taken When the Fault Code is Active

  • The ECM illuminates the amber CHECK ENGINE lamp immediately when the diagnostic runs and fails.
  • The multiplexed device will not operate.

Conditions for Clearing the Fault Code

  • To validate the repair, start the engine and let it idle for 1 minute.
  • The fault code status displayed by INSITE™ electronic service tool will change to INACTIVE immediately after the diagnostic runs and passes.
  • The ECM will turn off the amber CHECK ENGINE lamp after the diagnostic runs and passes.
  • The Reset All Faults command in INSITE™ electronic service tool can be used to clear active and inactive faults.

Shop Talk

This fault can occur 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.

It is possible to use INSITE™ electronic service tool to monitor multiplexed components.

Reference the appropriate OEM wiring diagram when troubleshooting circuits that utilize wiring supplied by the OEM.

For intermittent power supply and data link 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.

Refer to Troubleshooting Fault Code t05-286.

Last Modified:  16-Nov-2011