GASKET 4K5421 - Caterpillar

System Operation Description:During the installation of a Product Link 321 system, the wiring harness is connected to the existing Cat Data Link wiring on the machine. If this is not done properly, the continuity of the Cat Data Link wiring may be open intermittently. This condition may not be apparent immediately. This will cause a problem when you are trying to connect the Caterpillar Electronic Technician (Cat ET service tool) to the machine.
Cat ET may report that no ECM has been found.
Cat ET may not report every ECM that is on the machine.
Cat ET may report an ECM but the ECM will not have any data.If the wires for the Cat Data Link are reversed during the installation, the Product Link ECM will not be shown after connecting Cat ET to the machine.Test Step 1. VERIFY THAT THE CAT DATA LINK WIRES ARE NOT REVERSED.
Check that the positive Cat Data Link (CDL+) wire (893-GN(Green)) in the wiring harness for the Product Link is connected to the CDL+ wire (893-GN(Green) or 944-OR(Orange)) of the wire harness for the machine.
Check that the negative Cat Data Link (CDL-) wire (892-BR(Brown)) in the wiring harness for the Product Link is connected to the negative Cat Data Link (CDL-) wire (892-BR(Brown) or 945-BR(Brown)) of the wire harness for the machine. Expected Result:The Cat Data Link wires are properly connected.Results:
OK - The wires for the Cat Data Link are properly connected. Proceed to Test Step 2.
NOT OK - The wires for the Cat Data Link are reversed.Repair: Reinstall the Cat Data Link wires correctly and check the operation of the Product Link module by using Cat ET. STOPTest Step 2. CHECK THE WIRING WITH A MULTIMETER.
Turn off the machine and turn the disconnect switch to the OPEN position.
Measure the resistance of the negative Cat Data Link wire from the service connector (contact "E") to the location for the spliced Cat Data Link wire. Note the resistance.
Measure the resistance of the positive Cat Data Link wire from the service connector (contact "D") to the location for the spliced Cat Data Link wire. Note the resistance. Expected Result:The resistance in both wires is less than 5 ohms.Results:
OK - The resistance is less than 5 ohms. Proceed to Test Step 3.
NOT OK - The resistance is greater than 5 ohms. Repair the wiring harness.Repair: After repairing, resume the setup procedures for the installation of the Product Link.STOPTest Step 3. VERIFY THAT THE WIRING FOR THE CAT Data Link IS PROPERLY CONNECTED.
Check the spliced connections for the Cat Data Link that were made during the installation. Verify that all connections are clean and tight.
Reconnect the harness connectors that were disturbed during the installation. Ensure that all of the pins are correctly seated in the sockets.
Reconnect the cable from the service tool connector. Attempt to access the Cat Data Link by using Cat ET. Expected Result:Cat ET lists the ECM systems that are available on the machine. The ECM for the Product Link can be accessed.Results:
OK - Cat ET