0312975 JOHNSON SCREW,Cup & stop assy

Table 1
Diagnostic Codes Table    
Description     Conditions which Generate this Code     System Response    
1599-5 Engine Fan Blade Position Pull Solenoid current below normal     The Electronic Control Module (ECM) detects current that is below normal.     The code is logged.
The fan control solenoid is disabled.    
1599-6 Engine Fan Blade Position Pull Solenoid current above normal     The ECM detects current that is above normal.     The code is logged.
The fan control solenoid is disabled.    
1600-5 Engine Fan Blade Position Push Solenoid current below normal     The ECM detects current that is below normal.     The code is logged.
The fan control solenoid is disabled.    
1600-6 Engine Fan Blade Position Push Solenoid current above normal     The ECM detects current that is above normal.     The code is logged.
The fan control solenoid is disabled.    The blades on the variable pitch fan can be placed into the following three positions:
Push
Pull
NeutralThe purpose of a variable pitch fan is to clean debris from the radiator. This is done by temporarily reversing the direction of the air flow through the radiator. Temporarily reversing the air flow through the radiator is called purging the radiator. An automatic purge of the radiator will occur after a length of time, and an automatic purge of the radiator will occur if the coolant reaches a certain temperature. The operator can manually purge the radiator by pressing the manual purge button.
Illustration 1 g01399962
SchematicTest Step 1. Inspect Electrical Connectors and Wiring
Remove electrical power from the ECM.
Illustration 2 g01139425
ECM (1) J1/P1 connectors (2) J2/P2 connectors
Thoroughly inspect ECM connector J1/P1, ECM connector J2/P2, and all other connectors in the wiring harness. Refer to Troubleshooting, "Electrical Connectors - Inspect" for details.
Illustration 3 g01399974
P1 terminals that are associated with the variable pitch fan (P1-19) Manual purge switch (P1-21) Pull solenoid (P1-29) Digital return (P1-27) Push solenoid
Perform a 45 N (10 lb) pull test on each of the wires in the ECM connector and the sensor connectors that are associated with the active diagnostic code.
Check the ECM connector (allen head screw) for the proper torque. Refer to Troubleshooting, "Electrical Connectors - Inspect".Expected Result:All connectors, pins, and sockets are completely inserted and coupled. The harness and wiring are free of corrosion, of abrasion, and of pinch points. All connections and grounds are tight and free of corrosion.Results:
OK - The harness and wiring are OK. Proceed to Test Step 2.
Not OK - There is a problem with the harness and/or wiring.Repair: Repair the circuit.Verify that the repair eliminates the problem.STOPTest Step 2. Check the Resistance through the Solenoid
Remove electrical power from the ECM.
Disconnect the push/pull solenoid for the variable pitch fan.
Measure the resistance between terminal 1 (push solenoid) and terminal 2 (digital return).
Measure the resistance between terminal 4 (pull solenoid) and terminal 3 (digital return).Expected Result:Resistance is 25 5 Ohms.Results:
OK - The push/pull solenoid for the variable pitch fan has the correct resistance. Proceed to Test Step 3.
Not OK - The resistance is not acceptable. The push/pull solenoid for the variable pitch fan is faulty.Repair: Install a new push/pull solenoid for the variable pitch fan.Verify that the repair eliminates the problem.STOPTest Step 3. Check the Status of the Manual Purge Switch
Connect Caterpillar Electronic Technician (ET) to the service tool connector.
Restore electrical power to the ECM.
Observe the status for "Engine Fan Manual Purge Switch" on Cat ET while you operate the switch.
Remove electrical power from the ECM.Expected Result:The status of the switch is "On" when the switch is depressed. The status reads "Off" when the switch is released.Results:
OK - The status shows the expected result. The manual purge switch is working properly. Proceed to Test Step 5.
Not OK - The status does not show the expected result. The ECM does not recognize the input from the manual purge switch. Proceed to Test Step 4.Test Step 4. Check the Manual Purge Switch
Remove electrical power from the ECM.
Disconnect the connector for the manual purge switch.
Measure the continuity between terminal B (manual purge