24M Motor Grader Power Train Electronic Control System MID 027 - CID 1639 - FMI 09 Caterpillar

Conditions Which Generate This Code:

Illustration 1	g01389921
CAN Data Link

This diagnostic code is recorded when the Machine ECM does not receive expected information from the Machine Security System ECM for a period of more than five seconds.

System Response:

This failure results in events that are logged against an ECM that can not be explained directly. The Machine ECM cannot communicate with the Machine Security System ECM or the ECM appears to communicate intermittently.

Test Step 1. VERIFY THE HARDWARE AND THE SOFTWARE PART NUMBERS.

1. Verify that the following information is correct:

   • The part number of the flash software for the Machine ECM

   • The part number of the flash software for the Machine Security System ECM

   • The part number of the Machine ECM

   • The part number of the Machine Security System ECM

   Note: Consult your AVSpare Dealer for the correct part numbers of the flash software.

Expected Result:

All of the part numbers are correct.

Results:

• OK - All of the part numbers are correct. Proceed to Test Step 2.

• NOT OK - All of the part numbers are not correct.

  Repair: The Machine ECM or the Machine Security System ECM has the wrong part number or incorrect flash software is installed. Flash the correct software or replace the incorrect Machine ECM or the Machine Security System ECM with a module that has the correct part number. See the Troubleshooting, Testing and Adjusting, "Electronic Control Module (ECM) - Flash Programming" section for additional information.

  STOP

Test Step 2. INSPECT THE HARNESS CONNECTIONS.

1. Turn the disconnect switch to the OFF position.

2. Inspect all harness connections that are related to the CAN Data Link. Make sure that the connectors are clean and that the connections are tight.

3. Check the connectors for proper mating. Ensure that all the seals are present and in place.

4. Check the harness for signs of damage or signs of abrasion.

5. Check the wires at the connector. Ensure that the wires are secured tightly into the connector. Take care not to pull the wire out of the connector.

6. Check the exposed wires at the connectors for nicks or signs of abrasion.

7. Check for moisture inside the connector.

8. Check the connectors for dirty contacts or corroded contacts.

9. Check each contact and each socket of the machine harness connectors. Ensure that the contacts are properly installed. The contacts should mate correctly when the two pieces of the connector are placed together.

Expected Result:

The machine harness connectors are tight and free of corrosion.

Results:

• OK - The machine harness connectors are tight and free of corrosion. Proceed to Test Step 3.

• NOT OK - The machine harness connectors are in need of repair.

  Repair: Repair the machine harness or replace the machine harness.

  STOP

Test Step 3. CHECK FOR SHORTS TO GROUND

1. The disconnect switch remains in the OFF position.

2. Disconnect the machine harness connectors from all electronic control modules that use the CAN Data Link.

3. At the machine harness for the Machine ECM, measure the resistance between frame ground and connector contacts J2-67 (wire K900-YL(Yellow)) and J2-68 (wire K990-GN(Green)) of the circuit for the CAN Data Link.

Expected Result:

The resistance is greater than 5000 ohms.

Results:

• OK - The resistance is greater than 5000 ohms. The harness circuit resistance is correct. Proceed to Test Step 4.

• NOT OK - The resistance is less than 5000 ohms. The machine harness has failed.

  Repair: There is a short between frame ground and contacts J2-67 (wire K900-YL(Yellow)) and J2-68 (wire K990-GN(Green)) of the circuit for the CAN Data Link in the machine harness. Repair the machine harness or replace the machine harness.

  STOP

Test Step 4. CHECK FOR SHORT TO THE +BATTERY CIRCUIT

1. The disconnect switch remains in the OFF position.

2. All related electronic control modules remain disconnected from the machine harness.

3. At the machine harness connector for the Machine ECM, perform the checks that are listed here:

   • Measure the resistance between the connector contact J1-31 (wire 126-RD(Red)) and connector contact J2-67 (wire K900-YL(Yellow)).

   • Measure the resistance between connector contact J1-31 (wire 126-RD(Red)) and connector contact J2-68 (wire K990-GN(Green)).

Expected Result:

The resistance is greater than 5000 ohms.

Results:

• OK - The harness circuit resistance is correct. Proceed to Test Step 5.

• NOT OK - The resistance is less than 5000 ohms. The machine harness has failed.

  Repair: There is a short between the +battery circuit and contacts J2-67 (wire K900-YL(Yellow)) and J2-68 (wire K990-GN(Green)) of the circuit for the CAN Data Link in the machine harness. Repair the machine harness or replace the machine harness.

  STOP

Test Step 5. CHECK FOR OPEN HARNESS

1. The disconnect switch remains in the OFF position.

2. All related electronic control modules remain disconnected from the machine harness.

3. Check the circuit resistance for the CAN Data Link of the machine harness:

   • Measure the resistance between connector contact J2-67 (wire K900-YL(Yellow)) of the Machine ECM and connector contact 3 (wire K900-YL(Yellow)) of the Machine Security System ECM.

   • Measure the resistance between connector contact J2-68 (wire K990-GN(Green)) of the Machine ECM and connector contact 4 (wire K990-GN(Green)) of the Machine Security System ECM.

Expected Result:

The resistance measures less than 5 ohms.

Results:

• OK - The resistance is less than 5 ohms. The circuit for the CAN Data Link of the machine harness is correct. Proceed to Test Step 6.

• NOT OK - The resistance is greater than 5 ohms. The machine harness has failed.

  Repair: The circuit for the CAN Data Link is open in the machine harness. Repair the machine harness or replace the machine harness.

  STOP

Test Step 6. CHECK FOR ADDITIONAL DIAGNOSTIC CODES FOR THE OTHER ELECTRONIC CONTROL MODULES.

1. Turn the key start switch and the disconnect switch to the OFF position.

2. One at a time, reconnect the electronic control modules that use the CAN Data Link.

3. Turn the disconnect switch and the key start switch to the ON position.

4. After each of the electronic control modules has been reconnected, check for diagnostic codes that are logged against that electronic control module.

Expected Result:

Diagnostic codes are not present for the other electronic control modules.

Results:

• OK - Diagnostic codes are not present for the other electronic control modules. The Machine Security System ECM has failed.

  Repair: It is unlikely that the ECM has failed. Exit this procedure and perform this procedure again. If the failure is not found, replace the ECM.

  STOP

• NOT OK - Diagnostic codes are present for the other electronic control modules. The Machine ECM has failed.

  Repair: It is unlikely that the ECM has failed. Exit this procedure. Perform this procedure again. If the failure is not found, replace the ECM. See Troubleshooting, Testing and Adjusting, "Electronic Control Module (ECM) - Replace".

  STOP