Cummins ISB4.5 CM2150 Fault Code: 427 PID: SID 231 SPN: 639 FMI: 9 J1939 Data Link – Abnormal Update Rate.

Circuit Description
Devices such as ABS controllers, autoshift transmissions, ASR systems, electronic displays, electronic information systems, electronic service tools, and vehicle electronic control unit(s) (VECUs) can communicate with the ECM over the SAE J1939 data link. Messages sent from the devices are received by the ECM and used for controlling the engine. The ECM also transmits information to these devices over the SAE J1939 data link.

Component Location
The SAE J1939 data link wiring and the SAE J1939 devices vary by OEM options.

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 does not receive a valid J1939 message from a multiplexed device for more than 1second. The ECM detects an open or short circuit condition in the J1939 data link harness.

Action Taken When the Fault Code is Active
-The ECM will log the fault code immediately when the diagnostic runs and fails.
-The ECM will use a default state as an input for the multiplexed device.

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 the INSITE electronic service tool will change to INACTIVE immediately after the diagnostic runs and passes.
-The “Reset All Faults” command in the INSITE electronic service tool can be used to clear active and inactive faults.

Possible Causes
-Electrical problems with the SAE J1939 data link wiring such as grounded, shorted, or open circuits
-The ECM (or another SAE J1939 device) tying up communications by sending too many consecutive messages
-The external OEM controlling device has malfunctioned or can no longer transmit on the data link.