ALTERNATOR 5447866 - Caterpillar

Illustration 1 g01599614
Schematic of the Cat Data Link CircuitThis diagnostic code is recorded when the ECM does not receive expected information. The information from the Cat Data Link indicates the abnormal values in the readout. The possible causes of this diagnostic code are listed below. The causes are listed in order of probability: For machines equipped with the E-Fence feature, reference Troubleshooting, "E-Ceiling and Cab Avoidance - Troubleshoot"
Poor electrical connection at a machine harness connector
The circuit for the Cat Data Link in the machine harness is shorted to ground.
The circuit for the Cat Data Link in the machine harness is shorted to a power supply source.
The circuit for the Cat Data Link in the machine harness is open.System Response:The machine response is listed:
The service tool cannot detect the ECM.
The communication that is related to the codes is indicated by another ECM.Note: The Machine ECM is equipped with LED indicators that serve as a self-diagnostic check. With the key start switch ON, the following can be determined by the ECM indicator lights:
If all of the LED lights are Off, voltage is not being supplied to the Machine ECM. Check for power to the ECM.
If the yellow LED is Flashing, a communication error exists on the "CAN" data-link circuit.
If the yellow LED is constantly On, the Machine ECM software may be missing / not loaded.
If the red LED is Flashing, the Machine ECM has failed and may need replacement. Note: Ensure that the diagnostic code is active.Test Step 1. CHECK FOR OTHER CODES
Check for other diagnostic codes that are related to the Cat Data Link.Expected Result:There are other diagnostic codes that are showing.Results:
YES - Exit this procedure and perform the other procedures for the diagnostic codes that are shown. STOP
NO - There are not any other diagnostic codes. Proceed to Test Step 2.Test Step 2. INSPECT THE HARNESS CONNECTORS
Turn the disconnect switch OFF.
Inspect the connections for the machine harness that are related to the Cat Data Link.
Make sure that connectors are clean and tight.Expected Result:The machine harness is correct.Results:
OK - The machine harness is correct. Proceed to Test Step 3.
NOT OK - The machine harness is not correct.Repair: Repair the machine harness or replace the machine harness.STOPTest Step 3. CHECK FOR A SHORT TO GROUND
The disconnect switch remains OFF.
Disconnect the machine harness from all the 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 circuits of the Cat Data Link, contacts J1-33 (wire 893-GN) and J1-43 (wire 892-BR). Expected Result:The resistance is greater than 5000 ohms.Results:
YES - The resistance is greater than 5000 ohms. The harness circuit resistance is correct. Proceed to Test Step 4.
NO - The resistance is less than 5000 ohms. The machine harness has failed. There is a short between the frame ground and the Cat Data Link circuit in the machine harness. Repair: Repair the machine harness or replace the machine harness.STOPTest Step 4. CHECK FOR A SHORT TO A POWER SUPPLY