EXCITER 2423797 - Caterpillar

Illustration 1 g00984614
Schematic for the throttle position sensor Test Step 1. Inspect Electrical Connectors and Wiring
Turn the keyswitch to the OFF/RESET position.
Thoroughly inspect the J1/P1 ECM connector, the J61/P61 machine connector, and the J403/P403 sensor for the throttle signal connector. Refer to Troubleshooting, "Electrical Connectors - Inspect" for details.Expected Result:All connectors, pins, and sockets should be completely inserted and coupled. The harness and wiring should be free of corrosion, abrasion, and pinch points.Results:
OK - Proceed to Test Step 2.
Not OK - Repair: Repair the circuit.Verify that the repair eliminates the problem. Stop.Test Step 2. Inspect the Assembly for the Throttle Lever
Inspect the assembly for the throttle lever for components that are loose, bent, missing, or worn.
Slowly operate the throttle lever.Expected Result:The assembly for the throttle lever should operate smoothly without excessive drag.Results:
OK - The throttle lever functions properly. Proceed to Test Step 3.
Not OK - Repair: Repair the assembly for the throttle lever, as required. Stop.Test Step 3. Check the Status on an Electronic Service Tool
Connect an electronic service tool to the service tool connector.
Turn the keyswitch to the ON position.
Observe the status of "Throttle Signal" on an electronic service tool while you operate the throttle lever.Expected Result:The status should be approximately 0 percent when the throttle lever is at thelow idle position. The status should progressively increase to 100 percent when the throttle lever is moved to the high idle position.Note: This range can change depending on the adjustment of the assembly for the throttle lever.Results:
OK - The sensor for the throttle signal is working properly.Repair: Refer to Troubleshooting, "Electrical Connectors - Inspect" if the problem is intermittent. Stop.
Not OK - Proceed to Test Step 4.Test Step 4. Check the Supply Voltage at the Sensor
Install a 7X-6370 Adapter Cable (3 Pin DT Breakout) at the J403/P403 sensor for the throttle signal connector.
Turn the keyswitch to the ON position.
Measure the voltage across terminal A (+ Batt) and terminal B (Digital Sensor Return) at the breakout.Expected Result:The supply voltage should be 12 1 VDC.Results:
OK - The sensor is receiving the correct supply voltage. Proceed to Test Step 5.
Not OK - The correct supply voltage is not reaching the sensor.Repair: Proceed to Troubleshooting, "Digital Sensor Supply Circuit - Test". Stop.Test Step 5. Check the Isolated Signal Frequency and the Duty Cycle at the Sensor
Remove the wire from the harness side of P403:C (Throttle Signal).
Turn the keyswitch to the ON position.
Measure the frequency and the duty cycle between terminal B (Digital Sensor Return) and terminal C (Throttle Signal) at the J403/P403 breakout while you operate the throttle lever.
Turn the keyswitch to the OFF/RESET position.
Reinstall the wire in P403:C (Throttle Signal).Expected Result:The frequency should be between 150 and 1000 Hz. The duty cycle should be between 10 and 22 percent when the lever is moved to the low idle position. The duty cycle should be between 75 and 90 percent when the lever is moved to the high idle position.Results:
OK - The sensor is producing a valid signal. Proceed to Test Step