YOKE 9D2146 - Caterpillar

Illustration 1 g01966493
RS-485 network
This diagnostic code is recorded if the VIMSTM 3G Application ECM detects an abnormal RS-485 data link communication update rate.System Response:This failure results in events that are logged to the VIMS 3G Application ECM that cannot be explained. The VIMS 3G Application ECM cannot communicate correctly with the RS-485 data link.Test Step 1. VERIFY THE HARDWARE AND THE SOFTWARE PART NUMBERS
Verify that the following information is correct:
VIMS 3G Application ECM software part number
VIMS 3G Application ECM part numberNote: For the correct part numbers, consult the business unit that produces the product.Expected Result:All part numbers are correct.Results:
OK - All part numbers are correct. Proceed to Test Step 2.
NOT OK - All part numbers are not correct.Repair: Replace the incorrect ECM with an ECM that has the correct part number. See Testing and Adjusting, "Electronic Control Module (ECM) - Replace".Flash the correct configuration software. See Testing and Adjusting, "Electronic Control Module (ECM) - Flash Program".STOPTest Step 2. INSPECT THE HARNESS
Turn OFF the disconnect switch.
Inspect the RS-485 data link harness for the following:
Inspect the connectors, pins, and sockets for the following:
Cleanliness
Security
Proper mating
Seal condition
Moisture
Corrosion
Inspect the wires at the connector for the following:
Security
Nicks
AbrasionNote: Take care not to pull the wire out of the connector.
Inspect the harness for the following:
Damage
Abrasion
KinksExpected Result:The harness is in good condition.Results:
OK - The harness is in good condition. Proceed to Test Step 3.
NOT OK - The harness is not in good condition.Repair: Repair or replace the harness.STOPTest Step 3. CHECK THE 120 OHM TERMINATING RESISTORSThe disconnect switch remains OFF.
Disconnect both of the VIMS 3G ECMs from the RS-485 data link.
At the VIMS 3G Application ECM harness, measure the resistance between the following connector contacts:
Contact 17 (939-WH(White)) and Contact 18 (940-BU(Blue))
Contact 4 (920-BR(Brown)) and Contact 5 (921-YL(Yellow))Expected Result:The resistance is approximately 60 ohms.Results:
OK - The resistance is approximately 60