3512B Marine Auxiliary Engine Caterpillar

The CAT Data Link is used for communication between electronic modules. The CAT Data Link is used to communicate information from the Electronic Control Module (ECM) to the Caterpillar Monitoring System. The CAT Data Link is used for programming and troubleshooting the ECM.

The ECM communicates with the Caterpillar Monitoring System in order to share engine information.

The ECM communicates with the Caterpillar Electronic Technician (ET) in order to share status information. The ECM communicates with the Cat ET in order to share diagnostic information. The Cat ET can also be used to configure the ECM parameters on the engine. This information will not be available if communications fail between the ECM and the Cat ET.

The 3512B engine can be FLASH downloaded over the CAT Data Link.

Illustration 1	g00927438

Test Step 1. Check for Connector Damage.

1. Turn the battery circuit breaker to the OFF position.

2. Thoroughly inspect the ECM connectors J1/P1 and J2/P2. Inspect all of the other connectors. Perform the diagnostic functional test Troubleshooting, "Inspecting Electrical Connectors".

3. Perform a 45 N (10 lb) pull test on each of the wires in the ECM connector that are associated with the circuit.

4. Check the ECM connector (allen head screw) for the proper torque of 6.0 N·m (55 lb in).

5. Check the customer connector (allen head screw) for the proper torque of 2.25 ± 0.25 N·m (20 ± 2 lb in).

6. Check the harness and the wiring for abrasion and pinch points.

Expected Result:

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

Results:

• OK - The connectors and wiring are okay. Proceed to test step 2.

• Not OK - The connectors and/or wiring are not okay.

  Repair: Repair the connector and/or wiring or replace the connector and/or wiring.

  Stop.

Test Step 2. Check the CAT Data Link.

1. Connect the Cat ET to the service tool connector J60.

2. Turn the battery circuit breaker to the ON position.

3. Check for any LOGGED diagnostic codes.

4. Start the engine and read the status information on the Cat ET.

5. Observe the engine oil pressure and the coolant temperature on the Cat ET.

   Note: If some of the parameters, but not all of the parameters were displayed, the CAT Data Link is okay. Check the component that is associated with any missing parameter.

6. Stop the engine.

Expected Result:

The Cat ET should display the Status Information.

Results:

• OK - The CAT Data Link is operating correctly at this time.

  Repair: Check the system for any diagnostic codes.

  Stop.

• No Parameter Displayed. - There is a problem with the CAT Data Link. Proceed to test step 4.

• Service Tool Did Not Power Up. - The Cat ET or the Communication Adapter did not power up. Proceed to test step 3.

Test Step 3. Check the Power Supply Voltage.

1. Turn the battery circuit breaker to the OFF position.

2. Disconnect the Cat ET from the service tool connector J60.

3. Turn the battery circuit breaker to the ON position.

4. Measure the voltage between pin A and pin B at J60.

5. Turn the battery circuit breaker to the OFF position.

6. Reconnect Cat ET to the service tool connector J60.

Expected Result:

The voltage should be 24 ± 3 VDC.

Results:

• OK - The voltage is 24 ± 3 VDC. Proceed to test step 4.

• Not OK - The voltage is not 24 ± 3 VDC. There is a problem in the harness or electrical power supply.

  Repair: Verify that the battery circuit breaker or the engine control switch breaker are not tripped. Perform the diagnostic functional test Troubleshooting, "Electrical Power Supply".

  Stop.

Test Step 4. Check for Shorts in the Harness

1. Turn the battery circuit breaker to the OFF position.

2. Disconnect the ECM connectors J1/P1. Disconnect the service tool connector J60/P60. Disconnect any other devices that are attached to the Data Link circuit.

3. Measure resistance from P1-3 to P1-9.

4. Check the resistance at the following points on ECM connector P1:
   • P1-3 to P1-5

   • P1-9 to P1-5

   • P1-3 to P1-6

   • P1-3 to P1-4

   • P1-9 to P1-4

   • P1-3 to P1-11

   • P1-9 to P1-11

Expected Result:

Resistance should read more than 20,000 Ohms for each measurement.

Results:

• OK - The resistance is greater than 20,000 Ohms. The harness is free of shorts. Proceed to test step 5.

• Not OK - The resistance is less than 20,000 Ohms.

  Repair: Repair the connector and/or wiring or replace the connector and/or wiring.

  Stop.

Test Step 5. Check the Resistance through the Harness.

1. Turn the battery circuit breaker to the OFF position.

2. Disconnect the ECM connectors J1/P1. Disconnect any other devices that are attached to the Data Link circuit.

3. Use a suitable piece of wire to short P1-9 to P1-3.

4. Measure the resistance between pin D and pin E of the Service Tool Connector J60.

Expected Result:

Resistance should read less than 10 Ohms through the wires.

Results:

• OK - Resistance is less than 10 Ohms through the harness and connectors. Proceed to test step 6.

• Not OK - Resistance is greater than 10 Ohms. There is an open circuit in the harness or connectors.

  Repair: Repair the connector and/or wiring or replace the connector and/or wiring.

  Stop.

Test Step 6. Check Isolated Communication.

1. Reconnect the ECM connector.

2. Install the Cat ET.

3. Turn the battery circuit breaker to the ON position.

4. Read LOGGED Diagnostics.

5. Start the engine and read the status information on the Cat ET.

6. Read the Status information.

7. Stop the engine.

Expected Result:

The Cat ET should display any Diagnostics and Status Information.

Results:

• OK - Diagnostics and status information is displayed on the Cat ET.

  Repair: The problem may be intermittent. If the problem is intermittent, perform the diagnostic functional test Troubleshooting, "Inspecting Electrical Connectors".

  Stop.

• Not OK - Diagnostics and status information is not displayed on the Cat ET.

  Repair: Verify proper operation of the Cat ET and Communication Adapter on another engine.

  Stop.