0303750 JOHNSON GASKET,Carb.body to bowl

Table 1
Diagnostic Codes Table    
Code and Description    Conditions which Generate this Code    System Response    
248-9 @CatDatalinkLong@ not communicating     The battery voltage to the Electronic Control Module (ECM) has been above 9 VDC for the last two seconds.
The battery voltage to the ECM has been above 9 VDC for the last two seconds.
Communication was lost.     The ECM will log the diagnostic code.
All features that depend on the Cat Data Link will be disabled.    
562-9 Caterpillar Monitoring System abnormal update rate     The ECM has lost communications with the Monitoring System.     The diagnostic code is logged.
All features that depend on communications with the Monitoring System are disabled.    The Cat Data Link is a two wire electrical connection that is used for communication between electronic modules such as the engine Electronic Control Module (ECM), the machine ECM, electronic transmission controls, electronic dash displays, and Cat Electronic Technician (ET).The ECM communicates with display modules in order to share engine information and diagnostics for the electronic system.
Illustration 1 g01901153
SchematicTest Step 1. Inspect Electrical Connectors and Wiring
Remove electrical power from the ECM.
Illustration 2 g01139425
ECM (1) J1/P1connectors (1) J21/P1connectors
Thoroughly inspect ECM connector J1/P1 and machine connector J3/P3. Refer to Troubleshooting, "Electrical Connectors - Inspect" for details.
Illustration 3 g01851193
P1 terminals that are associated with the Cat Data Link (P1-3) Cat Data Link − (P1-9) Cat Data Link +
Perform a 45 N (10 lb) pull test on each of the wires that are associated with the Cat Data Link.
Check the allen head screw on each ECM connector for the proper torque. Also, check the allen head screw on the customer connector for the proper torque. Refer to Troubleshooting, "Electrical Connectors - Inspect" for the correct torque values.Expected Result:All connectors, pins, and sockets should be completely inserted and coupled. The harness and wiring are free of corrosion, of abrasion, and of pinch points.Results:
OK - Proceed to Test Step 2.
Not OK - Repair: Repair the circuit.Verify that the repair eliminates the problem.STOPTest Step 2. Check for Shorts in the Harness
Disconnect ECM connector J1/P1.
Disconnect all modules from the Cat Data Link.
Disconnect Cat ET from the service tool connector.
Measure the resistance between P1:3 (Cat Data Link −) and P1:9 (Cat Data Link +).
Measure the resistance between P1:9 (Cat Data Link +) and chassis ground.
Measure the resistance between P1:3 (Cat Data Link −) and chassis ground.Expected Result:The resistance is greater than 20,000 Ohms for each measurement.Results:
OK - Proceed to Test Step 3.
Not OK - There is a short circuit in the harness or connectors.Repair: Repair the circuit.Verify that the repair eliminates the problem.STOPTest Step 3. Check the Resistance Through the Harness
Use a suitable piece of wire to short J42:D (Cat Data Link +) and J42:E (Cat Data Link −) at the service tool connector.
Measure the resistance between P1:9 (Cat Data Link +) and P1:3 (Cat Data Link −).
Measure the resistance across the Cat Data Link at the other modules.Expected Result:The resistance is less than 10 Ohms for each measurement.Results:
OK - The Cat Data Link is OK.Repair: Refer to Troubleshooting, "Electrical Connectors - Inspect" if the problem is intermittent.STOP
Not OK - There is an open circuit or excessive resistance in the harness or connectors.Repair: Repair the circuit.Verify that the repair eliminates the problem.STOP