TACHOMETER 3N8160 - Caterpillar

Illustration 1 g06164312
Proprietary CAN data link circuit
The possible causes of this diagnostic code are:
The software that is installed on the VIMS Main ECM modules is incorrect.
The VIMS Main ECM module is not receiving all expected parameters from another ECM on the circuit.
The ECM is unable to obtain a network address.
A new ECM has been installed but the ECM is not the correct part number.Note: A loss of power in the system to one ECM can cause another ECM to activate this diagnostic code combination. Ensure that the ECM modules with this diagnostic code are powered up before proceeding with the procedure.Test Step 1. VERIFY THE ECM PART NUMBERSNote: Consult your Caterpillar Authorized Dealer for the correct part numbers.
Verify the part numbers of all components related to the faulty data link circuit.Expected Result:The part numbers are correct.Results:
OK - The part numbers are correct. Proceed to Test Step 2.
NOT OK - A module has the wrong part number. Replace the incorrect module with a module that has the correct part number. Flash the correct software.Repair: Note: See the Troubleshooting, "ECM Software - Install" section of this manual for additional information.Proceed to Test Step 3.Test Step 2. CHECK the software for the correct versionNote: Consult your Cat dealer for the correct part numbers of the flash software.
Connect Cat® Electronic Technician (Cat® ET) to the service tool connector.
Use Cat ET to verify that the version of software is correct for the ECM.Expected Result:The software is correct.Results:
OK - The software is correct. Proceed to Test Step 3.
NOT OK - The proper software is not installed.Repair: Flash the proper software to the appropriate ECM. Cycle the key switch to initialize the new software.For flashing software, refer to Testing and Adjusting, "Electronic Control Module (ECM) - Flash Program".Proceed to Test Step 3.STOPTest Step 3. CHECK THE RESISTANCE of the data link circuit
Turn off the key start switch and the battery disconnect switch.
Measure the resistance of the datalink between ECM datalink (+) wire and the datalink (-) wire on the wiring harness connector of the ECM. Refer to the electrical wiring diagram in this section of the manual.Expected Result:The resistance measures 60&OHacgr;+/-10&OHacgr;.Results:
OK - The resistance measures 60&OHacgr;+/-10&OHacgr;. Proceed to Test Step 4.
NOT OK - The resistance is less than 50&OHacgr;. There are more than 2 terminating resistors installed in the wiring harness or a short circuit exists.Repair: Remove any extra terminating resistors or repair or replace the harness.Proceed to Test Step 4.STOP
NOT OK - The resistance is 120&OHacgr;+/-10&OHacgr;. There is a problem with a terminating resistor.Repair: Check the resistance on the terminating resistor. If the resistor is not within specification, replace.Proceed to Test Step 4.STOPTest Step 4. CHECK if the diagnostic code remains
Inspect the contacts of the harness connectors and clean the contacts.
Reconnect all harness connectors.
Turn the disconnect switch and the key start switch to the on position.
Operate the machine.
Check to see if the diagnostic code is active.Expected Result:The diagnostic code is no longer active.Results:
OK - The diagnostic code is no longer active. The initial diagnostic code