0586228 JOHNSON RELAY & CABLE ASSY.

Illustration 1 g00945950
SchematicTest Step 1. Inspect Electrical Connectors and Wiring
Turn the keyswitch to the OFF/RESET position.
Thoroughly inspect the J1/P1 ECM connector, the connector for the fuel level sender, and any other connectors in the circuit. Refer to Troubleshooting, "Electrical Connectors - Inspect" for details.Expected Result:All connectors, pins, and sockets should be completely inserted and coupled. The harness and wiring should be free of corrosion, abrasion, and pinch points. All connections and grounds should be tight and free of corrosion.Results:
OK - Proceed to Test Step 2.
Not OK - Repair: Repair the circuit. 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 the Fuel Level
Visually check the fuel level in the tank.
Compare the fuel level in the tank to the indicator on the fuel level sender.Expected Result:The fuel level in the tank should correlate with the indicator on the fuel level sender.Results:
OK - Proceed to Test Step 3.
Not OK - The indicator on the fuel level sender does not reflect the actual fuel level in the tank.Repair: Replace the fuel level sender.Verify that the repair eliminates the problem. Stop.Test Step 3. Check the Status of the Fuel Level on an Electronic Service Tool
Turn the keyswitch to the OFF/RESET position.
Connect the electronic service tool to the service tool connector.
Turn the keyswitch to the ON position.
Observe the status of "Fuel Gauge" on the electronic service tool.Note: The status of "Fuel Gauge" on the electronic service tool represents the percentage of fuel in the tank.
Turn the keyswitch to the OFF/RESET position.Expected Result:The status of "Fuel Gauge" should correlate with the fuel level in the tank.Results:
OK - The fuel level sensor appears to be operating correctly at this time.Repair: Refer to Troubleshooting, "Electrical Connectors - Inspect" if the problem is intermittent. Stop.
Not OK - A valid signal is reaching the ECM, but the ECM is not reading the signal properly.Repair: Verify your results before replacing the ECM. Refer to Troubleshooting, "Replacing the ECM". Proceed to Test Step 4.Test Step 4. Check the Resistance of the Fuel Level Sender.
Disconnect the fuel level sender from the harness.
Measure the resistance between the terminals on the receptacle for the fuel level sender.
Reconnect the fuel level sender.Expected Result:The resistance should be less than 100 Ohms.Note: The resistance should be between 0 and 3.5 Ohms when the indicator is on "F". The resistance should be between 92 and 98 Ohms when the indicator is on "E".Results:
OK - The fuel level sender appears to be OK. Proceed to Test Step 5.
Not OK - The resistance is out of the range.Repair: Replace the fuel level sender.Verify that the repair eliminates the problem. Stop.Test Step 5. Check the Supply Voltage to the Fuel Level Sender
Disconnect the fuel level sender from the harness.
Turn the keyswitch to the ON position.
Measure the voltage across the terminals of the harness.Expected Result:The supply voltage should measure 4.5 to 5.5 VDC.Results:
OK - The fuel level sender is receiving the correct supply voltage. Proceed to Test Step 6.
Not OK - The fuel level sender is not receiving the correct supply voltage.Repair: Repair the circuit.Verify that the repair eliminates the problem. Stop.Test Step 6. Verify that the Diagnostic Code is Still Active.
Connect the electronic service tool to the data link connector.
Turn the ignition key switch to the ON position. Wait at least 15 seconds for activation of the diagnostic codes.
Monitor the "Active Diagnostic Code" screen of the electronic service tool. Check and record active diagnostic codes.
Determine if the problem is related to an open circuit diagnostic code or a short circuit diagnostic code.Expected Result:Either a short circuit diagnostic code is active or an open circuit diagnostic code is active.Results:
SHORT Circuit - A short circuit diagnostic code is active at this time. Proceed to Test Step 7.
OPEN Circuit - An open circuit diagnostic code is active at this time. Proceed to Test Step 8.Test Step 7. Check the Harness for Shorts
Illustration 2 g00946043
P1 connector
Illustration 3 g00946046
Connector for the monitoring system
Ensure that the keyswitch is in the OFF/RESET position and that the fuel level sender is disconnected from the harness.
Disconnect the J1/P1 connector and the connector for the J99/P99Caterpillar monitoring system.
Measure the resistance between P1:5 (- Battery) and P99:9 (Fuel Level Sender).
Leave the connectors disconnected.Expected Result:The resistance should be greater than 20,000 Ohms.Results:
OK - The harness is not shorted. Proceed to Test Step 8.
Not OK - There is a short in the harness.Repair: Repair the harness.Verify that the repair eliminates the problem. Stop.Test Step 8. Check for Opens in the Harness
Install a jumper wire between P1:5 (- Battery) and P99:9 (Fuel Level Sender).
Check the resistance between both terminals of the plug for the fuel level sensor.
Remove the jumper wire and reconnect the fuel level sensor.Expected Result:The resistance should be less than 10 Ohms.Results:
OK - The harness is good. Proceed to Test Step 9.Test Step 9. Check the Status of the Fuel Level on the Electronic Service Tool
Ensure that all of the connectors are connected.
Turn the keyswitch to the ON position.
Check for active diagnostic codes on the electronic service tool.
Observe the status of "Fuel Gauge" on the electronic service tool.Note: The status of "Fuel Gauge" on the electronic service tool represents the percentage of fuel level in the tank.
Turn the keyswitch to the OFF/RESET position.Expected Result:The status of "Fuel Gauge" should correlate with the fuel level in the tank and there should not be any active diagnostic codes for the fuel level sensor.Results:
OK - The fuel level sensor appears to be operating correctly at this time.Repair: Refer to Troubleshooting, "Electrical Connectors - Inspect" if the problem is intermittent. Stop.
Not OK - A valid signal is reaching the ECM, but the ECM is not reading the signal properly.Repair: Verify your results before replacing the ECM. Refer to Troubleshooting, "Replacing the ECM". Stop.