GASKET 2P8697 - Caterpillar

Conditions Which Generate This Code:This diagnostic code is associated with the CAT Data Link. The FMI 9 means that the ECM has determined that an abnormal update has occurred.
Illustration 1 g00530246
System Schematic For CAT Data LinkNote: When a customer communication module is connected to a single generator set, "B+" is connected directly from wire 10. When a customer communication module is connected to multiple generator sets, "B+" must be connected through a diode. Refer to Figure 1.On EUI engines ( 3500B), the GSC+ uses the CAT Data Link in order to communicate with the engine ECM. The CAT Data Link consists of two wires that connect the GSC+ to the engine ECM.The possible causes of a CID 248 FMI 9 are listed below.
A short to the battery positive terminal ("B+") of either of the two CAT Data Link wires
A short to the battery negative terminal ("B-") of either of the two CAT Data Link wiresThe GSC+ cannot detect an open in the circuit of the CAT Data Link. The GSC+ treats a CID 248 FMI 9 as an alarm fault. Active alarm faults are shown on the display when the "Alarm Codes" key is pressed. The engine control switch (ECS) is in any position except the OFF/RESET position. Troubleshoot and repair the wiring. See Testing And Adjusting, "Schematics And Wiring Diagrams". Clear the fault from the fault log after troubleshooting is complete.Test Step 1. CHECK THE BATTERY POSITIVE TERMINALS
Ensure that there are not shorts between +battery and either of the CAT Data Link wires.
Turn the ECS to OFF/RESET.
Disconnect both cables from the battery.
Measure the resistance between the positive