AccuGrade® GPS Using The CD550A Display (GPS/ATS/Sonic/Cross Slope) Caterpillar

Illustration 1	g01082074
Schematic for CAT data link

This diagnostic code is recorded when the implement control ECM is unable to communicate with the machine's power train ECM through the CAT data link. This diagnostic code is recorded when the implement control ECM does not receive expected information. The possible causes of this diagnostic code are listed below. The causes are listed in order of probability:

• 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 the +battery.

• The circuit for the CAT data link in the machine harness is open.

System Response:

This failure results in events that are logged against the implement control ECM in order to determine the allowed automatic blade control mode. The machines power train control ECM cannot communicate with the implement control ECM. The communication may be intermittent. Prior to performing this procedure, check for an active diagnostic code of CID 0248 FMI 09. If this diagnostic code is present exit this procedure and perform the diagnostic procedure for CID 0248 FMI 09.

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 implement control ECM

   • The part number of the machine's implement control ECM

   • The part number of the flash software for the machine's power train ECM

   • The part number of the machine's power train ECM

   Note: Contact your dealership's Technical Communicator for a possible consultation with Caterpillar.

Expected Result:

All the part numbers are correct.

Results:

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

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

  Repair: The installed machine's power train ECM has the wrong part number or the incorrect software is installed. Replace the machine's incorrect power train ECM with a module that has the correct part number. Flash the correct software. See the Testing and Adjusting, "Module - Flash Program" section of this manual.

  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 CAT data link. Make sure that the connectors are clean and 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 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 pin 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 from all electronic control modules that use the CATdata link.

3. At the machine harness for the implement control ECM, measure the resistance between contacts J1-20 (wire 893-GN) and J1-10 (wire 892-BR) of the CAT data link and frame ground.

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 the CAT data link circuit in the machine harness. Repair the machine harness or replace the machine harness.

  STOP

Test Step 4. CHECK THE MACHINE HARNESS FOR A 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 implement control ECM, perform the checks that are listed here:
   • Measure the resistance between the connector contact J1-31 (wire 110-RD) and connector contact J1-10 (wire 893-GN).

   • Measure the resistance between connector contact J1-31 (wire 110-RD) and connector contact J1-20(wire 892-BR).

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 the circuits of the CAT data link circuit 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 continuity of the CAT data link circuit in the machine harness:
   • Measure the resistance between connector contact J1-10 (wire 893-GN) of the implement control ECM and connector contact J1-9 (wire 893-GN) of the power train control ECM.

   • Measure the resistance between connector contact J1-20 (wire 892-BR) of the implement control ECM and connector contact J1-3 (wire 892-BR) of the power train control ECM.

Expected Result:

The resistance measures less than 5 ohms.

Results:

• OK - The resistance is less than 5 ohms. The CAT data link circuit in 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 CAT data link circuit 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 CAT 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 the Event List for diagnostic codes that are logged against the electronic control module.

Expected Result:

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

Results:

• OK - Diagnostic codes are not present for the other electronic control modules in the event list.

  Repair: The implement control ECM has failed. It is unlikely that the ECM has failed. Exit this procedure. Perform this procedure again. If the failure is not found, check the +battery contacts and ground contacts of the ECM. If these contacts are correct, replace the ECM.

  STOP

• NOT OK - Diagnostic codes are present for the other electronic control modules (ECM) in the event list.

  Repair: The power train ECM has failed. 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 the Testing and Adjusting, "Module - Replace" section of this manual.

  STOP