Troubleshooting for Marine Engine Electronic Displays Caterpillar

1. Turn the keyswitch to the "OFF" position.

2. Check the ECM connectors, the customer connectors, and wiring for damage or incorrect attachment.

3. Check for the correct installation of the wires for the J1939 data link. Refer to Installation Guide, "J1939 Data Link Wiring " for installation information.

4. Check the connectors for the following components for abrasion, corrosion, or incorrect attachment.

   • Messenger

   • Harness and wiring

   Ensure that the 165-0200 Cable As is securely connected to the Messenger.

5. Verify that the negative battery connections are secure and free from corrosion.

6. Verify that the belts and all connections for the charging system are secure and tight.

Expected Result:

All connectors, pins and sockets should be completely coupled and/or inserted and the harness and wiring should be free of corrosion, of abrasion, and of pinch points.

Results:

• OK - Proceed to Test Step 2.

• Not OK -

  Repair: Perform the following repair:

  Repair the connectors or wiring and/or replace the connectors or the wiring. Ensure that all of the seals are properly in place and ensure that the connectors are completely coupled.

  Verify that the repair eliminates the problem.

  STOP

Test Step 2. Check Battery Voltage at the Display Connector

1. Disconnect the display connector.

2. Turn the keyswitch to the "ON" position.

3. Use a voltmeter and measure the DC voltage from terminal 1 to terminal 2 of the display connector.

Pull on each of the wires in the connector.

Expected Result:

The battery voltage should be 11 to 13.5 VDC for 12 volt systems and 23 to 27 VDC for 24 volt systems.

Results:

• OK - The battery voltage is within specifications. Proceed to Test Step 3.

• Not OK - The battery voltage is not within specifications.

  Repair: Isolate the problem and repair the problem.

  Verify that the repair eliminates the problem.

  STOP

Test Step 3. Verify Correct Wiring for the Display

1. Disconnect the J1 ECM connector and measure the resistance between the connection for the J1939 Data Link + and the connection for the J1939 Data Link -. Refer to Table 1 for pin numbers.
   Show/hide table

   Table 1

   Terminal locations for the Data Link on the J1 ECM Connector
   Engine	J1939 Data Link +	J1939 Data Link −	Shield
   3126B 3500B Series II C7 C9 C12 C15 C18	J1-50	J1-34	J1-42
   3176C 3196 3406E	J1-33	J1-39	J1-26
   3412E 3500B C30 C32	J1-16	J1-10	J1-15

Expected Result:

The range of the resistance is 57 Ohms to 63 Ohms.

Results:

• OK - The measurement is within specifications. Proceed to Test Step 5.

• Not OK - The range of the resistance is 114 Ohms to 126 Ohms. A terminating resistor is missing.

  Repair: Install the missing resistor.

  Refer to the Schematic in order to determine the location of the missing resistor.

  Proceed to Test Step 5.

• Not OK - Resistance is less than 50 Ohms. Proceed to Test Step 5.

• Not OK - Resistance is greater than 130 Ohms. Proceed to Test Step 4.

Test Step 4. Check Terminating Resistors

Verify that only two terminating resistors exist on the data link. One resistor should be located on each end of the data link.

For additional information, refer to the Installation Guide, "J1939 Cable Specifications". In addition, refer to the Schematic for your particular engine.

Expected Result:

One terminating resistor is correctly installed at each end of the data link.

Results:

• OK - The terminating resistors are installed correctly. Proceed to Test Step 5.

• Not OK - The terminating resistors are not installed correctly.

  Repair: Ensure the proper installation of the terminating resistors. Verify that the repair eliminates the original problem.

  STOP

Test Step 5. Check the Data Link for a Short in the Harness

1. Turn the keyswitch to the OFF position.

2. Isolate the circuit for the J1939 Data Link.

   1. Disconnect the vessel's connectors from the ECM for each of the engines that are on the J1939 Data Link.

   2. Disconnect the connections for the J1939 Data Link from the Messenger.

   3. Disconnect all of the other modules that communicate on the J1939 Data Link.

      Note: Failure to isolate the network completely will result in resistance measurements that are inaccurate.

3. Measure the resistance between the following terminals at the ECM connector for one of the engines:

   Note: Refer to Table 1 for terminal locations on J1 ECM connector.

   • J1939 Data Link +

   • J1939 Data Link −

   • Shield for the J1939 Data Link

Expected Result:

The correct resistance for all measurements is an open circuit.

Results:

• OK - All resistance measurements indicated an open circuit. There are no shorts in the harness. Leave the connectors for the J1939 Data Link disconnected. Proceed to Test Step 6.

• Not OK - A short circuit was indicated by at least one of the resistance measurements.

  Repair: There is a short circuit in the harness. Repair the harness or replace the harness. Verify that the repair eliminates the original problem.

  STOP

Test Step 6. Check the J1939 Data Link for an Open in the Harness

1. Ensure that the harness connectors for the J1939 Data Link are disconnected.

2. Fabricate a jumper wire that can be used to jumper the wiring that is for the J1939 Data Link at the various connectors.

   Note: Refer to Table 1 for terminal locations on J1 ECM connector.

3. One at a time, install the jumper wire across the terminals for the J1939 Data Link + and the J1939 Data Link − at each of the ECM connectors. Measure the resistance at the ECM connector at one of the engines for each of the circuits that are shorted.

4. One at a time, install the jumper wire across the terminals for the J1939 Data Link + and the J1939 Data Link − at each of the modules that are on the network. Measure the resistance at the ECM connector at one of the engines for each of the circuits that are shorted.

5. One at a time, install the jumper wire across the terminals for the J1939 Data Link − and the shield for the J1939 Data Link at each of the ECM connectors. Measure the resistance at the ECM connector at one of the engines for each of the circuits that are shorted.

6. One at a time, install the jumper wire across the terminals for the J1939 Data Link − and the shield for the J1939 Data Link at each of the modules that are on the network. Measure the resistance at the ECM connector at one of the engines for each of the circuits that are shorted.

Expected Result:

The correct resistance for all measurements is a short circuit.

Results:

• OK - All resistance measurements indicated a short circuit. There are no open circuits in the harness. Restore the harness wiring to the original configuration. Proceed to Test Step 7.

• Not OK - An open circuit was indicated by at least one of the resistance measurements.

  Repair: There is an open circuit in the harness. Repair the harness or replace the harness. Verify that the repair eliminates the original problem.

  STOP

Test Step 7. Check the Messenger Display

1. Remove the Messenger and place the display near the ECM.

2. Connect a 165-0201 Cable between the receptacle connector to the ECM and the receptacle connector to the Messenger.

3. Power up the ECM and the Messenger.

Expected Result:

The Messenger operates properly.

Results:

• OK - The problem is in the wiring to the Messenger.

  Repair: Make the necessary repairs.

  STOP

• Not OK - A "Data Link Error" exists. The "Data Link Error" message will appear if the Marine Power Display (MPD) loses the signal to the data link or if the ECM does not have the correct software.

  Repair: Perform the following procedure.

  1. Connect the Messenger display to another engine.

  2. If the Messenger operates properly on the different engine, replace the ECM.

  3. Verify that the repair eliminates the problem.

  4. If the Messenger does not function properly on the different engine, replace the Messenger display.

  STOP