994H Large Wheel Loader VIMSTM 3G / Product Link Caterpillar

Illustration 1	g02568941
VIMSTM 3G Main ECM Product Link circuit

This diagnostic code is recorded when the VIMS^TM 3G Main ECM telemetry has an abnormal update rate on the data-link.

Test Step 1. VERIFY THAT THE BROADCAST SYSTEM IS FUNCTIONING CORRECTLY

1. Verify that the broadcast system is operating correctly.

Expected Result:

The broadcast system is operating correctly.

Results:

• YES - The broadcast system is operating correctly. Proceed to Test Step 2.

• NO - The broadcast system is not operating correctly.

  Repair: Repair the broadcast system.

  STOP

Test Step 2. CHECK FOR HARNESS OPEN

1. Turn off the keyswitch and the disconnect switch.

2. Disconnect the connector from the VIMS 3G Main ECM .

3. Disconnect the RS232 port from the broadcast system.

4. Measure the resistance of the circuits listed in Table 1:
   Show/hide table

   Table 1

   VIMS 3G Main ECM		RS232 broadcast port
   contact 13 (wire N957-PK)	to	contact 5 (wire N957-PK)
   contact 22 (wire N960-OR)	to	contact 7 (wire N960-OR)
   contact 31 (wire N979-GR)	to	contact 8 (wire N979-GR)
   contact 23 (wire N970-YL)	to	contact 9 (wire N970-YL)
   contact 30 (wire N973-BR)	to	contact 10 (wire N973-BR)

Expected Result:

All resistance is low.

Results:

• OK - All resistance is low. Proceed to Test Step 3.

• NOT OK - All resistance is not low. The harness has failed.

  Repair: Repair or replace the harness.

  STOP

Test Step 3. CHECK THE HARNESS FOR SHORTS TO GROUND

The disconnect switch remains off and the harness remains disconnected from the VIMS 3G Main ECM and the broadcast system.

1. Measure the resistance from frame ground to the following VIMS 3G main ECM connector contacts:
   • Contact 13 (wire N957-PK)

   • Contact 22 (wire N960-OR)

   • Contact 23 (wire N970-YL)

   • Contact 30 (wire N973-BR)

   • Contact 31 (wire N979-GN)

Expected Result:

All resistance is high.

Results:

• OK - All the resistance is high. The machine harness is correct. The ECM may have failed. However, ECM failure is unlikely.

  Repair: Exit this procedure and perform this procedure again. Contact your Cat dealer technical communicator.

  STOP

• NOT OK - A resistance is low. The harness has failed.

  Repair: Repair or replace the harness.

  STOP