7746450_053 Volvo.Penta TUFLO 500

Illustration 1 g00935574
Test Step 1. Check for Connector Damage.
Turn the keyswitch to the OFF position.
Thoroughly inspect the ECM connector J1/P1 and the machine connector J2/P2. Inspect all of the other connectors. Refer to the diagnostic functional test Troubleshooting, "Inspecting Electrical Connectors" for details.
Perform a 45 N (10 lb) pull test on each of the wires in the ECM connector that are associated with the circuit.
Check the ECM connector (allen head screw) for the proper torque of 2.25 0.25 N m (20 2 lb in).
Check the machine connector (allen head screw) for the proper torque of 2.25 0.25 N m (20 2 lb in).
Check the harness and the wiring for abrasion and for pinch points.Expected Result:The connectors and wiring are free of the following problems: damage, corrosion, abrasion and incorrect attachmentResults:
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 connectors or wiring and/or replace the connectors or wiring. Stop.Test Step 2. Check for a Solenoid Internal Short or Open.
Disconnect the connector for the engine fan control solenoid J48/P48.
Measure the resistance of the solenoid between J48-1 and J48-2.Expected Result:The resistance is between 2.8 0.3 Ohms.Results:
OK - The resistance is between 2.8 0.3 Ohms. Proceed to Test Step 3.
Not OK - The resistance is not between 2.8 0.3 Ohms. The solenoid is internally shorted or open.Repair: Replace the solenoid. Stop.Test Step 3. Check the Voltage at the Solenoid.
Connect Cat ET to the cab service tool connector J31. Start Cat ET.
Turn the Battery disconnect switch to the ON position.
Turn the keyswitch to the ON position. The engine should be off.
Select the override for the engine fan on Cat ET.
Set the override for the engine fan to 100 percent.
Measure the voltage between P48-1 and P48-2 at the engine fan control solenoid.Expected Result:The voltage is greater than 1.0 VDC. The typical voltage is 5.3 VDC at the normal operating temperature.Results:
OK - The voltage is greater than 1.0 VDC. The voltage is correct.Repair: The voltage reaches the solenoid. If the system operates correctly, check the mechanical operation of the solenoid. Stop.
Not OK - The voltage is not greater than 1.0 VDC. The voltage is not correct. Proceed to Test Step 4.Test Step 4. Check the Voltage at the ECM.
Turn the keyswitch to the OFF position. The engine should be off.
Remove wire F700-BU from pin P1-60 at ECM connector J1/P1. Install a jumper into the socket for P1-60.
Remove wire E799-BR from ECM connector P1-32. Install a jumper into the socket for P1-32.
Turn the keyswitch to the ON position. The engine should be off.
Select the override for the engine fan on Cat ET.
Set the override for the engine fan to 100 percent.
Measure the voltage between the jumper wires at P1-60 and P1-32.
Turn the keyswitch to the OFF position.
Remove the jumper wires and reconnect all wires.Expected Result:The voltage is greater than 1.0 VDC. The typical voltage is 5.3 VDC at normal operating temperature.Results:
OK - The voltage is greater than 1.0 VDC. The voltage is correct. There is an open circuit or excessive resistance in the harness between the ECM and the solenoid. Proceed to Test Step 5.
Not OK - The voltage is not greater than 1.0 VDC. The voltage is not correct.Repair: Replace the ECM. Refer to the diagnostic procedure Troubleshooting, "Replacing the ECM". Stop.Test Step 5. Check for a Short Circuit in the Harness.
Turn the keyswitch to the OFF position.
Disconnect the connector for the engine fan control solenoid J48/P48.
Disconnect ECM connector J1/P1.
Measure the resistance between P48-1 and P48-2.
Measure the resistance between P48-1 and the chassis ground.
Measure the resistance between P48-2 and the chassis ground.Expected Result:The resistance is greater than 20,000 Ohms.Results:
OK - The resistance is greater than 20,000 Ohms. Proceed to Test Step 6.
Not OK - The resistance is less than 20,000 Ohms. There is a short circuit in the harness between the ECM and the solenoid.Repair: Repair the connectors or wiring and/or replace the connectors or wiring. Stop.Test Step 6. Check for an Open Circuit in the Harness.
Install a jumper wire between P48-1 and P48-2.
Measure the resistance between P1-60 and P1-32 at the ECM connector P1.
Remove the jumper. Reconnect all connectors.Expected Result:The resistance is less than 5 Ohms.Results:
OK - The resistance is less than 5 Ohms.Repair: The problem may be intermittent. Reconnect all wiring and connectors. Check the circuit for proper operation. Stop.
Not OK - The resistance is more than 5 Ohms.Repair: There is excessive resistance or an open in the wiring and/or in the connectors. Repair the connectors or wiring and/or replace the connectors or wiring. Stop.