5030415 JOHNSON NUT, Screen

Illustration 1 g00694476
Test Step 1. Inspect Electrical Connectors and Wiring
Turn the keyswitch to the OFF/RESET position.
Check the connectors and wiring for the following problems: damage, corrosion, abrasion and incorrect attachment. Pay close attention to the following areas:
ECM connector J1/P1
Connector for the J1939 Data Link
Connector for the terminating resistor
Wiring harness from the ECM back to the connector for the J1939 Data LinkRefer to Troubleshooting, "Electrical Connectors - Inspect" for more information.Expected Result:The connectors and wiring should be free of the following problems: damage, corrosion, abrasion and incorrect attachment.Results:
OK - Proceed to Test Step 2.
Not OK - Repair: Repair the J1939 Data Link circuit. Verify that the repair eliminates the problem. Stop.Test Step 2. Check Active Diagnostic Codes
Connect the Electronic Technician to the cab data link connector.
Turn the keyswitch to the ON position. Do not start the engine.
Monitor the screen for active diagnostic codes on ET. Record any active diagnostic codes.Expected Result:No diagnostic codes are active.Results:
OK - Repair: Refer to Troubleshooting, "Troubleshooting Without a Diagnostic Code" in order to determine other possible causes of the problem. Stop.
Not OK - the diagnostic code is active. Proceed to Test Step 3.Test Step 3. Check Input Voltage to the ECM
Turn the keyswitch to the ON position. Do not start the engine.
Use signal reading probes to measure the voltage between P1:48 and P1:61. Wiggle the harness during the measurement in order to reveal an intermittent condition.
Use ET to check for the following logged diagnostic codes: 168-00, 168-01 and 168-02. If any of the previous diagnostic codes are logged there could be an intermittent problem in the circuit for the input voltage to the ECM.Expected Result:The input voltage to the ECM should be within 1.0 VDC of the battery voltage.Results:
OK - Proceed to Test Step 4.
Not OK - Repair: Refer to Troubleshooting, "Electrical Power Supply Circuit - Test" and Electrical System Schematic. Make any necessary repairs. Stop.Test Step 4. Check resistance through the Harness
Turn the keyswitch to the OFF position.
Disconnect the J1/P1 connector and the J1939 Data Link connector.
Measure the resistance between P1:34 and P1:50. Wiggle the harness during the measurement in order to reveal an intermittent condition.Expected Result:The resistance should measure 114 Ohms to 126 Ohms.Results:
OK - Proceed to Test Step 5.
Not OK - The resistance is greater than 20,000 Ohms. There is an open circuit in the harness or the terminating resistor is missing or open.Repair: Repair the harness and/or replace the harness. If the terminating resistor is missing or damaged, install a new resistor. Stop.
Not OK - The resistance is less than 10 Ohms.Repair: There is a short in the harness or the terminating resistor is shorted. Replace the harness or the terminating resistor. Stop.Test Step 5. Check for a Short Circuit.
Leave J1/P1 and J1939 Data Link disconnected.
Disconnect the terminating resistor.
Measure the resistance between P1:34 and P1:50. Wiggle the harness during the measurement in order to reveal an intermittent condition.
Continue this procedure with the following combinations:
P1;34 and pin A of J1939 +
P1:50 and pin B of J1939 -
P1:34 and the ground stud
P1:50 and the ground studExpected Result:The resistance should be greater than 20,000 Ohms.Results:
OK - Proceed to Test Step 6.
Not OK - There is a short circuit in the harness.Repair: Repair the harness and/or replace the harness. Stop.Test Step 6. Check for an Open Circuit
Short terminals A and B of the J1939 Data Link connector .
Measure the resistance between P1:34 and P1:50.
Remove the jumper wire from pin A and pin B on the J1939 Data Link connector.
Measure the resistance between P1:34 and P1:50.
Measure the resistance between P1:42 and pin C on the J1939 Data Link connector.
Reconnect the terminating resistor.Expected Result:The resistance should be less than 10 Ohms.Results:
OK - Proceed to Test Step 7.
Not OK - There is an open circuit in the harness.Repair: Repair the harness and/or replace the harness. Stop.Test Step 7. Use a Test ECM to Check the J1939 Data Link
Temporarily connect a test ECM.
Repeat this procedure.
If the problem is resolved with the test ECM in place, reconnect the suspect ECM.
If the problem returns with the suspect ECM in place, replace the ECM. Verify that the repair eliminates the problem.Results:
OK - Stop.
Not OK - The problem is in the CAN Data Link bridge adapter to the Machine Control System. Make any necessary repairs. Stop.