10238083 Mariner INSTALLATION MANUAL, 225/250/275/300 Verado

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Test Step 1. Verify That the Coolant Level is Acceptable
Ensure that the coolant level for the engine is appropriate. Refer to Operation and Maintenance Manual, "Cooling System Coolant Level - Check" for more information.Expected Result:The coolant is at an acceptable level.Results:
OK - Proceed to Test Step 2.
Not OK - Repair: Diagnose the reason for a low coolant level.Refer to the Troubleshooting, "Troubleshooting Without a Diagnostic Code" section in this manual for more information.Verify that the repair eliminates the problem.STOPTest Step 2. Inspect Electrical Connectors and Wiring
Turn the keyswitch to the OFF/RESET position.
Thoroughly inspect ECM connector J1/P1, and J47/P47 Coolant Flow Switch Connector. Refer to Troubleshooting, "Electrical Connectors - Inspect" for details.Expected Result:All connectors, pins, and sockets are completely inserted and coupled. The harness and wiring are free of corrosion, of abrasions, and of pinch points. All connections and grounds are tight and free of corrosion.Results:
OK - Proceed to Test Step 3.
Not OK - Repair: Repair the circuit.Verify that the repair eliminates the problem.STOPTest Step 3. Check Status of the Coolant Flow Switch on the Caterpillar Electronic Technician (Cat ET)
Turn the keyswitch to the OFF/RESET position.
Connect Cat ET to the data link connector.
Disconnect J47/P47 Coolant Flow Switch Connector.
Use a suitable piece of wire to short P47:1 (Coolant Flow Switch Connector) to P47:2 (Digital Sensor Return).
Turn the keyswitch to the ON position.
Observe the status of "Engine Coolant Flow" on Cat ET.
Turn the keyswitch to the OFF/RESET position.Expected Result:The status indicates "Flow" with the jumper wire in place.Results:
OK - The ECM and the wiring are operating correctly. Proceed to Test Step 4.
Not OK - Proceed to Test Step 5.Test Step 4. Check the Coolant Flow Switch.
Remove the coolant flow switch from the engine.
Manually close the coolant flow switch. Ensure that excessive force is not required to close the switch.
Measure continuity between J47:1 (Coolant Flow Switch Connector) and J47:2 (Digital Sensor Return) with the switch in the closed position.Expected Result:The switch closes easily and there is continuity between J47:1 (Coolant Flow Switch Connector) and J47:2 (Digital Sensor Return) with the switch in the closed position.Results:
OK - There may be a mechanical problem with the cooling system of the engine.Repair: Diagnose the cooling system of the engine. Refer to the Troubleshooting, "Troubleshooting Without a Diagnostic Code" section in this manual.Verify that the repair eliminates the problem.STOP
Not OK - There is a problem with the coolant flow switch.Repair: Replace the coolant flow switch with a new switch.Verify that the repair eliminates the problem.STOPTest Step 5. Check for Shorts in the Harness from the Coolant Flow Switch to the ECM
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ECM connector P1
Turn the keyswitch to the OFF/RESET position.
Disconnect ECM connector J1/P1.
Disconnect J47/P47 Coolant Flow Switch Connector.
Measure the resistance between P1:26 (Coolant Flow Switch Connector) and engine ground.
Measure the resistance between P1:26 (Coolant Flow Switch Connector) and all the other pins. Also measure the resistance between P1:29 Digital Sensor Return and all the other pins to ground.Expected Result:The resistance is greater than 20,000 Ohms.Results:
OK - Proceed to Test Step 6.
Not OK - There is a short between the ECM and the connector for the coolant flow switch.Repair: Repair the circuit.STOPTest Step 6. Check for Open Circuits in the Harness from the Coolant Flow Switch to the ECM
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J1/P1 breakout
Turn the keyswitch to the OFF/RESET position and install a 7X-1715 Adapter Cable As (40-PIN BREAKOUT) at ECM connector J1/P1.
Use a suitable piece of wire to short P1:26 (Coolant Flow Switch) and P1:29 (Digital Return) at the breakout.
Disconnect J47/P47 Coolant Flow Switch Connector.
Measure the resistance between P47:1 (Coolant Flow Switch Connector) and P47:2 (Digital Sensor Return).Expected Result:The resistance is less than 10 Ohms.Results:
OK - Proceed to Test Step 7.
Not OK - There is a open circuit in the wiring harness between the coolant flow switch and the ECM.Repair: Repair the circuit.Verify that the repair eliminates the problem.STOPTest Step 7. Check the Supply Voltage at the ECM
Illustration 4 g00677413
J1/P1 breakout
Disconnect J47/P47 Coolant Flow Switch Connector.
Use a suitable piece of wire to short P1:26 (Coolant Flow Switch) to P1:29 (Digital Sensor Return) at the breakout.
Turn the keyswitch to the ON position.
Observe the status of "Engine Coolant Flow" on Cat ET.Expected Result:The status indicates "Flow" with the jumper wire in place.Results:
OK - The ECM is responding correctly.Repair: Refer to Troubleshooting, "Electrical Connectors - Inspect" if the problem is intermittent.STOP
Not OK - The ECM is not responding correctly.Repair: Verify your results.Replace the ECM. Refer to Troubleshooting, "Replacing the ECM" before replacing the ECM.Verify that the repair eliminates the problem.STOP