ROLLER G.-S.F. 7F6398 - Caterpillar

Illustration 1 g02729672
Schematic of the CAT Data Link
This diagnostic code is associated with the information from the Chassis ECM to the Steering ECM. The information is sent via the Cat® Data Link or the J1939 Data Link. The Cat® Data Link and the J1939 Data Link are connected to two inputs of the Steering ECM.The FMI 9 means that the Steering ECM has not received expected information from the Chassis ECM.The possible causes of this diagnostic code are listed:
Terminating resistors on the J1939 Data Link are faulty
An ECM or smart device is not powering up
Lack of key switch input to an ECM or smart device (where applicable)
Excessive noise on the Data Link circuit
An open or a poor connection in the Data Link circuit
Software configuration mismatch
The Chassis ECM has failed. An ECM failure is unlikely.
The Steering ECM has failed. An ECM failure is unlikely.Note: The following test procedure may create other diagnostic codes. Ignore these diagnostic codes and clear the diagnostic codes when the original diagnostic code has been corrected. Ensure that the diagnostic code of CID 296 FMI 9 is active before performing this procedure.Test Step 1. DETERMINE THE DATA LINK COMPANION CODE THAT IS ACTIVE
Check the list of active diagnostic codes to determine the "companion" diagnostic codes that are active:CID 247 FMI 9 - SAE J1939 Data LinkCID 248 FMI 9 - Cat® Data LinkResults:
OK - Both the CID 247 FMI 9 and the CID 248 FMI 9 codes are active, check power to the Steering ECM.STOP
OK - The CID 248 FMI 9 diagnostic code is active indicating that the problem is in the Cat® Data Link. To perform the troubleshooting procedure for the Cat® Data Link, proceed to the diagnostics for CID 248 FMI 9.
OK - The CID 247 FMI 9 diagnostic code is active indicating that the problem is in the SAE J1939 Data Link. To perform the troubleshooting procedure for the SAE J1939 Data Link, proceed to the diagnostics for CID 247 FMI 9.