0337789 JOHNSON LOCATING BRKT., Rear

Illustration 1 g00656850
Typical schematic
Illustration 2 g01072804
P2 ECM connector (P2-7) Solenoid return (P2-19) Engine fan control solenoidTest Step 1. Inspect Electrical Connectors and Wiring
Turn the keyswitch to the OFF position.
Thoroughly inspect the ECM connectors J2/P2. Inspect the connector for the engine fan control solenoid. Refer to 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 6.0 N m (55 lb in).
Check the customer 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:All connectors, pins, and sockets are completely coupled and/or inserted. The harness and wiring are free of corrosion, of abrasion, and of pinch points.Results:
OK - The harness and wiring are OK. Proceed to Test Step 2.
Not OK - There is a problem in the connectors and/or wiring.Repair: Repair the connectors or wiring and/or replace the connectors or wiring. 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.STOPTest Step 2. Check for an Internal Short or an Open in the Coil of the Engine Oil Renewal Solenoid
Disconnect the connector for the engine fan control solenoid J41/P41.
Measure the resistance of the solenoid coil between J41-1 and J41-2.Expected Result:The resistance of the coil is between 2 and 4.6 Ohms.Results:
OK - The resistance of the coil is between 2 and 4.6 Ohms. Proceed to Test Step 3.
Not OK - The resistance of the coil is not between 2 and 4.6 Ohms. The solenoid coil is internally shorted or open.Repair: Replace the solenoid.STOPTest Step 3. Check the Voltage at the Engine Oil Renewal Solenoid
Connect Cat ET to the cab service tool connector J42. Start Cat ET.
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 P41-1 and P41-2 at the engine fan control solenoid.Expected Result:The voltage is greater than 3.8 VDC. The typical voltage is 8.5 VDC at the normal operating temperature.Results:
OK - The voltage is greater than 3.8 VDC. The typical voltage is 8.5 VDC at the normal operating temperature. 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 3.8 VDC. The typical voltage is 8.5 VDC at the normal operating temperature. 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 terminal P2-19 at ECM connector J2/P2. Install a wire jumper into the socket for P2-19.
Remove wire E799-BR from ECM connector P2-7. Install a wire jumper into the socket for P2-7.
Reconnect ECM connector J2/P2.
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 P2-19 and P2-7.
Turn the keyswitch to the OFF position.
Remove the jumper wires and reconnect all wires.Expected Result:The voltage is greater than 3.8 VDC. The typical voltage is 8.5 VDC at normal operating temperature.Results:
OK - The voltage is greater than 3.8 VDC. The typical voltage is 8.5 VDC at normal operating temperature. 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 3.8 VDC. The typical voltage is not 8.5 VDC at the normal operating temperature. The Voltage is not correct.Repair: Replace the ECM. Refer to Troubleshooting, "Replacing the ECM".STOPTest 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 J41/P41.
Disconnect ECM connector J2/P2.
Measure the resistance between P2-19 and every terminal on ECM connector P2.
Measure the resistance between P2-19 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.STOPTest Step 6. Check for an Open Circuit in the Harness
Install a wire jumper between P41-1 and P41-2.
Measure the resistance between P2-19 and P2-7 at the ECM connector P2.
Remove the wire 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 connectors. Repair the connectors or wiring and/or replace the connectors or wiring.STOP