0322285 JOHNSON SCREW,Cam

Illustration 1 g01012536
Typical example
Illustration 2 g00725481
Throttle Position Versus PWM Input
Test Step 1. Check for Connector Damage.
Turn the Engine Control Switch (ECS) to the OFF/RESET position.
Thoroughly inspect the ECM connectors J1/P1 and J2/P2. Inspect the wiring and the connectors that are associated with the circuit. Refer to the diagnostic functional test Troubleshooting, "Inspecting Electrical Connectors" for details on inspecting wiring and connectors.
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 1 N m (53 9 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, and the harness and wiring are free of corrosion, of abrasion or of pinch points.Results:
OK - The connectors and wiring are OK. If you are troubleshooting either the primary speed control or the secondary speed control from the customer, proceed to Test Step 2. If you are troubleshooting the local speed control on the instrument panel, proceed to Test Step 5.
Not OK - The connectors and/or wiring need repair.Repair: Repair the connectors or wiring and/or replace the connectors or wiring.STOPTest Step 2. Check the Throttle Position on the Caterpillar Electronic Technician (ET).
Connect Cat ET to the service tool connector.
Turn the ECS to the STOP position.
Observe the position of the throttle on Cat ET.
Adjust the customer's throttle to the lowest setting.
Start at the lowest position. Slowly adjust the customer's throttle to the highest setting. Monitor the position of the throttle on Cat ET. Expected Result:The throttle position on Cat ET is 0 percent at the lowest setting and 0 to 100 percent as the throttle is adjusted to the highest setting.Results:
OK - The throttle is operating correctly.Repair: There may be an intermittent problem. If the problem is intermittent, refer to Troubleshooting, "Inspecting Electrical Connectors" for details on inspecting wiring and connectors.STOP
Not OK - The throttle position on Cat ET does not change correctly. Proceed to Test Step 3.Test Step 3. Check the Duty Cycle at the Customer Connector.
Turn the ECS to the OFF/RESET position.
Remove the wire for the throttle signal from the customer's connector. Refer to Illustration 1 for the schematic of the circuit.
Set the multimeter to "VDC". Press the "Hz" button twice so that the % symbol is displayed.
Place the red probe of the digital multimeter on the terminal for the throttle signal on the customer connector. Place the black probe of the multimeter on the −Battery terminal.
Turn the ECS to the STOP position.
Measure the percent duty cycle of the throttle signal. Adjust the throttle from the lowest position to the highest position.
Turn the ECS to the OFF/RESET position.
Replace all connectors and wires. Expected Result:The duty cycle is 5 to 10 percent at the lowest setting. The duty cycle is 90 to 95 percent at the highest setting.Results:
OK - The duty cycle and throttle position readings are correct. Proceed to Test Step 4.
Not OK - The duty cycle reading is not correct. The throttle position signal is not reaching the ECM.Repair: Check the signal from the customer's connector to the customer's speed control.STOPTest Step 4. Check the Duty Cycle at the ECM Connector.
Turn the ECS to the OFF/RESET position.
Remove the ECM connector P1 from the ECM. Remove the throttle signal wire from the ECM connector P1. Refer to Illustration 1 for the schematic of the circuit.
Reconnect the ECM connector J1/P1.
Set the multimeter to "VDC". Press the "Hz" button twice so that the % symbol is displayed.
Place the red probe of the digital multimeter on the throttle signal wire that was removed from ECM connector P1. Place the black probe of the multimeter on the −Battery terminal.
Turn the ECS to the STOP position.
Measure the percent duty cycle of the throttle signal. Move the throttle from the lowest setting to the highest setting.
Turn the ECS to the OFF/RESET position.
Replace all connectors and wires. Expected Result:The duty cycle is 5 to 10 percent at the lowest setting. The duty cycle is 90 to 95 percent at the highest setting.Results:
OK - The duty cycle and the throttle signal are correct.Repair: Temporarily replace the ECM and perform the test again. If the problem is resolved, the ECM is faulty. Permanently replace the ECM. Refer to the diagnostic procedure Troubleshooting, "Replacing the ECM".STOP
Not OK - The duty cycle reading is not correct. The throttle signal is not reaching the ECM.Repair: Repair the wire between ECM connector P1 and the customer connector.STOPTest Step 5. Check the Throttle Position on the Caterpillar Electronic Technician (ET).
Turn the ECS to the STOP position.
Observe the position of the throttle on Cat ET.
Turn the local speed control potentiometer that is on the instrument panel to the lowest setting.
Start at the low idle position. Slowly turn the speed adjust potentiometer in the other direction. Monitor the position of the throttle on Cat ET. Expected Result:The throttle position on Cat ET reads 0 percent at the lowest setting and 0 to 100 percent as the speed adjust potentiometer is adjusted.Results:
OK - The local speed control is operating correctly.Repair: There may be an intermittent problem. If the problem is intermittent, refer to Troubleshooting, "Inspecting Electrical Connectors" for details on inspecting wiring and connectors.STOP
Not OK - The throttle position on Cat ET does not change correctly. Proceed to Test Step 6.Test Step 6. Check the Supply Voltage to the Local Speed Control.
Turn the ECS to the STOP position.
Connect the red probe of the digital multimeter to the +B terminal of the local speed control. Connect the black probe of the digital multimeter to the −B terminal of the local speed control.
Measure the voltage across the terminals of the local speed control. Expected Result:The voltage is 24 3 VDC.Results:
OK - The voltage is 24 3 VDC. The local speed control is receiving the correct