COOLER-FUEL 3916410 - Caterpillar

Illustration 1 g01151994
Schematic of the CAT Data Link circuitThis diagnostic code is associated with the CAT Data Link. This diagnostic code is recorded when the Caterpillar Monitoring System ECM does not receive expected information. For example, engine speed or actual gear information is not received from other electronic control modules through the CAT Data Link. This diagnostic code causes the readouts, that are dependent upon the CAT Data Link information, to indicate abnormal values.This FMI 09 means that the Power Train/Chassis Electronic Control Module (ECM) has determined that a valid code is not received from the Caterpillar Monitoring System ECM.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 0248 FMI 09 is active before performing this procedure.The possible causes of this diagnostic code are listed in the order of probability:
A poor electrical connection at a machine harness connector.
A circuit in the CAT Data Link is shorted to frame ground.
The CAT Data Link circuit in the machine harness is shorted to the +battery.
The CAT Data Link circuit in the machine harness is open.System Response:The Automatic Retarder Control (ARC) system would not operate properly if the signal for the CAT Data Link is lost unexpectedly.The identification code from the Caterpillar Monitoring System is not available. If the ECM had never been able to communicate with the Caterpillar Monitoring System, the ECM would not have allowed the machine to start. The ECM would not have allowed the machine to shift. Also, the ECM would not have allowed the machine to disengage the parking brake.Test Step 1. CHECK FOR OTHER CODES
Check for similar diagnostic codes that are logged against other electronic control modules. If a similar diagnostic code is found, exit this test and perform the corresponding procedure(s) for the other diagnostic codes that are shown.Expected Result:Other diagnostic codes are showing.Results:
YES - Exit this procedure and perform the CID/FMI procedure for the diagnostic codes that are shown. Stop.
NO - There are no other related diagnostic codes. Proceed to Test Step 2. Test Step 2. INSPECT THE HARNESS CONNECTORS
Turn the key start switch and the battery disconnect switch to the OFF position.
Inspect the connections of the machine harness that are related to the CAT Data Link.
Make sure that connectors are clean and tight.Expected Result:The machine harness connectors are correct.Results:
OK - The machine harness connectors are correct. Proceed to Test Step 3.
NOT OK - The machine harness connectors are not correct. Repair: Repair the machine harness connectors or replace the machine harness connectors. Stop.Test Step 3. CHECK FOR A SHORT TO FRAME GROUND
The key start switch and the battery disconnect switch remain in the OFF position.
Disconnect the machine harness from all electronic control modules that use the CAT Data Link.
At the machine harness connector for the ECM, measure the resistance between frame ground and the CAT Data Link circuits contacts J1-20 (wire 892-BR) and J1-10 (wire 893-GN).Expected Result:The resistance measurement