FA307779 Force BAFFLE, AIR INTAKE W/SILENCER

Table 1
Correlation Between Switch Positions and Engine Speed    
Throttle Switch Position    Desired Engine Speed    
1     800    
2     1020    
3     1160    
4     1300    
5     1470    
6     1590    
7     1700    
8     1800    
9     1900    
10     1980    
Illustration 1 g00783112
Schematic for the throttle switchTest Step 1. Inspect Electrical Connectors and Wiring
Turn the keyswitch to the OFF position.
Check the allen head screw on each ECM connector and the customer connector for the proper torque. Refer to Troubleshooting, "Electrical Connectors - Inspect" for the correct torque values.
Check the harness and wiring for corrosion, for abrasion, and for pinch points from the throttle switch to the ECM.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.Results:
OK - Proceed to Test Step 2.
Not OK - Repair: Repair the circuit.Verify that the repair eliminates the problem.STOPTest Step 2. Use the Caterpillar Electronic Technician (ET) to Check the Throttle Switch
Connect Cat ET to the service tool connector.
Turn the keyswitch to the ON position.
Ensure that the machine is not operating in the throttle backup mode.
Observe the status of the throttle switch and the throttle inputs on Cat ET while you operate the throttle switch in each position.Expected Result:Cat ET displays a duty cycle between 0 and 100 percent.Results:
OK - The throttle switch is operating properly at this time. Repair: Refer to Troubleshooting, "Electrical Connectors - Inspect" if the problem is intermittent.STOP
Not OK - There is a problem with the circuit for the throttle switch. Proceed to Test Step 3.Test Step 3. Check the Throttle Command at the Machine Control Module.
Turn the keyswitch to the ON position.
Ensure that the machine is not operating in the throttle backup mode.
Use a multimeter to monitor the percent duty cycle of the throttle command at P1 socket 44 of the machine control module. Adjust the throttle switch from the low idle position to the high idle position.Expected Result:The percent duty cycle is between five percent and ten percent at low idle. The percent duty cycle increases to 90 percent to 95 percent at high idle.Results:
OK - The throttle command is correct. Proceed to Test Step 4.
Not OK - The throttle command is not correct. There may be a problem with the throttle switch or with the machine control module.Repair: Refer to the electrical schematic for your machine for more information.STOPTest Step 4. Check the Throttle Command at the ECM
Turn the keyswitch to the ON position.
Illustration 2 g01117132
ECM connector P1 (P1-61) -BATT (P1-63) -BATT (P1-65) -BATT (P1-66) Throttle command
Use a multimeter to monitor the percent duty cycle of the throttle command between ECM connectors P1-65 and P1-66 (throttle command) and ECM connectors P1-61 and P1-63 (-battery). Adjust the throttle switch from the low idle position to the high idle position. Note: Certain operating conditions may limit the percent duty cycle of the throttle. Refer to the System Operation Manual and the Testing and Adjusting Manual for the machine for information on the machine controls.Expected Result:The percent duty cycle is between five percent and ten percent at low idle. The percent duty cycle increases to 90 percent to 95 percent at high idle.Results:
OK - The throttle command is correct. The ECM is not processing the command properly. Verify that the ECM is receiving the correct battery voltage. If the ECM is receiving the correct battery voltage, replace the ECM.Repair: Refer to Troubleshooting, "Replacing The ECM" before replacing the ECM.STOP
Not OK - The throttle command is not correct. There is a problem in the harness or connectors between the machine control module and the ECM. Repair the circuit. Verify that the repair eliminates the problem. STOP