TUBE AS 9G9886 - Caterpillar

System Operation Description:The Cat Data Link is used for communication between electronic modules. The Cat Data Link is used to communicate information from the engine's Electronic Control Module (ECM) to the Electronic Monitoring System(EMS). The Cat Data Link is used for programming and troubleshooting the ECM.The ECM communicates with the EMS through the sharing of electronic system diagnostics and engine information.The ECM communicates with a Caterpillar Electronic Technician (ET) in order to share status and diagnostic information. Cat ET can also be used to configure the ECM parameters on the engine. This information will not be available if communications fail between the ECM and Cat ET.
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Bypass Harness (Engine Monitoring System)Test Step 1. Check the Electrical Connectors and the Wiring
Turn the battery switch for the ECM to the OFF position.
Turn the breaker at the battery to the OFF position.
Thoroughly inspect the ECM connector J1/P1. Inspect all of the other connectors. Refer to Troubleshooting, "Inspecting Electrical Connectors" for details.
Perform a 45 N (10 lb) pull test on each of the wires in the ECM connector that are associated with the circuit.
Check the ECM connector (allen head screw) for the proper torque.
Check the customer connector (allen head screw) for the proper torque.
Check the harness and the wiring for abrasion and pinch points.Expected Result:All connectors, pins, and sockets are completely coupled and/or inserted. The harness and wiring are free of corrosion, of abrasion or of pinch points.Results:
OK - The wiring and connectors are OK. Proceed to Test Step 2.
Not OK - Repair the wiring and connectors or replace the wiring or the connectors. Ensure that all of the seals are properly connected. Verify that the repair eliminates the problem.STOPTest Step 2. Verify the problem
Turn the breaker at the battery to the ON position.
Turn the battery switch for the ECM to the ON position.
Determine if the EMS displays a random error message or if the Caterpillar Monitoring System displays a CID-FMI 248-12 Cat Data Link malfunction diagnostic code.
Determine if the tachometer for the EMS displays a random EE message.Note: The EMS may properly operate for some period of time.Expected Result:The EMS displays any of the following errors:
Random error message
CID-FMI 248-12 Cat Data Link malfunction diagnostic code
Random EE message on the tachometerResults:
OK - The problem is NOT in the ECM or in the EMS display. Proceed to Test Step 3.
Not OK - Proceed to Test Step 4.Test Step 3. Install a Data Booster
Turn the battery switch for the ECM to the OFF position.
Install a 143-4518 Resistor Gp (Passive Data Booster) on the engine's ECM. Refer to the engine schematic for more information.
Turn the battery switch for the ECM to the ON position.
Determine if the display module is working properly with the 143-4518 Resistor Gp (Passive Data Booster).Expected Result:The display module is working properly.Results:
OK - STOP
Not OK - The display module is not working properly when the 143-4518 Resistor Gp (Passive Data Booster) is installed.Repair: Verify that the connections on the Cat Data Link wires are good. If the connections are good, then