3512B Engine for SPF343, SPS343, and SPT343 Pumpers Caterpillar

The CAT Data Link is used for communication between electronic modules. The Electronic Control Module (ECM) communicates with an Caterpillar Electronic Technician (ET) in order to share information about the engine system and any diagnostic codes that may be active. The CAT Data Link is used for programming and troubleshooting the engine ECM. 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.

Illustration 1	g00860752
Typical example

Test Step 1. Check for Connector Damage.

1. Turn circuit breaker "CB-8" to the OFF position.

2. Thoroughly inspect the ECM connectors J1/P1 and J2/P2. Inspect all of the other connectors. Refer to Troubleshooting, "Inspecting Electrical Connectors" for details.

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:

The connectors and wiring should be free of the following problems: damage, corrosion, abrasion and incorrect attachment.

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. Start the Cat ET.

2. Turn circuit breaker "CB-8" 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 for the Battery Voltage.

1. Turn circuit breaker "CB-8" to the OFF position.

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

3. Turn circuit breaker "CB-8" to the ON position.

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

5. Turn circuit breaker "CB-8" to the OFF position.

6. Reconnect the 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 circuit breaker "CB-8" is not tripped. Perform the diagnostic functional test Troubleshooting, "Electrical Power Supply".

  Stop.

Test Step 4. Check for Shorts in the Harness

1. Turn circuit breaker "CB-8" to the OFF position.

2. Disconnect the ECM connectors J1/P1. Disconnect the Cat ET from the service tool connector J60. 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 circuit breaker "CB-8" 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. Start the Cat ET.

3. Turn circuit breaker "CB-8" 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 refer to 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.