CM870 and ISX Engines – FAULT CODE 426

SAE J1939 Data Link Communication


Fault Code: 426
PID: S231
SPN: 639
FMI: 2/2
LAMP: None

Communication between the electronic control module (ECM) and another device on the SAE J1939 data link has been lost.

None on performance. SAE J1939 devices possibly do not operate.

SAE J1939 Data Link Circuit

Circuit Description

Devices such as ABS controllers, autoshift transmissions, ASR systems, electronic displays, electronic information systems, electronic service tools, and 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 ECM is located on the intake side of the engine, near the front. The SAE J1939 data link wiring and the SAE J1939 devices vary by OEM options.

Shop Talk

This fault occurs whenever the ECM starts communicating with any other device using the SAE J1939 data link and then can no longer transmit on the data link. Possible causes of this fault include:

  • 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.

Refer to Troubleshooting Fault Code t05-426

Last Modified:  01-Sep-2010