PLATE 4I6366 - Caterpillar

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Typical duty cycle versus throttle position The signal from the throttle position sensor has a specific frequency. The frequency of the signal must be between 150 Hz and 1000 Hz or the ECM will activate a 091-08 diagnostic code.
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Schematic for the throttle position sensorTest Step 1. Inspect the Electrical Connectors and the Wiring
Turn the keyswitch to the OFF position.
Thoroughly inspect the connectors. Inspect the connections on the throttle position sensor. Refer to Troubleshooting, "Electrical Connectors - Inspect".
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P1 terminal that is associated with the throttle position sensor (P1-4) Digital Supply (P1-5) Digital Return (P1-66) Throttle position
Perform a 45 N (10 lb) pull test on each of the wires that are associated with the throttle position sensor.
Check the allen head screw on each ECM connector for the proper torque.
Check the harness and wiring for abrasions and for pinch points from the throttle position sensor to the ECM and from the throttle position sensor to the battery.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 wiring and the connectors are OK. Proceed to Test Step 2.
Not OK - There is a problem with the wiring and/or the connectors.Repair: Repair the wiring and/or the connectors. Replace parts, if necessary. Ensure that all of the seals are properly connected. Verify that the repair eliminates the problem.STOPTest Step 2. Check the Throttle Position with Cat ET.
Connect the Caterpillar Electronic Technician (ET) to the service tool connector. Refer to Troubleshooting, "Electronic Service Tools".
Turn the keyswitch to the ON position. The engine should be off.
Observe the throttle position reading on Cat ET.
Depress the throttle and release the throttle.Expected Result:The output should be "0 percent" when the pedal is released. The output should increase to "100 percent" when the throttle pedal is fully depressed.The output should be between "7 percent" at the low idle position and "95 percent " at the high idle position or a 91-08 diagnostic code will be activated.Results:
OK - The ECM is receiving the correct signal from the sensor. The problem seems to be resolved.Repair: There may be an intermittent fault. Refer to Troubleshooting, " Electrical Connectors - Inspect".STOP
Not OK - The ECM is not receiving a correct signal from the sensor. There may be a problem in the harness. Proceed to Test Step 3.Test Step 3. Check for Supply Voltage at the Throttle Position Sensor
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Disconnect the harness connector at the sensor.
Turn the keyswitch to the ON position. The engine should be OFF.
Measure the voltage between terminal A (supply voltage) and terminal B (digital return) on the harness side of the connector.
Turn the keyswitch to the OFF position.Expected Result:The supply voltage for the sensor mesures 8 0.4 VDC at the sensor connector.Results:
OK - The correct voltage is measured at the sensor connector. The sensor is receiving the correct supply voltage. Proceed to Test Step 4.
Not OK - The supply voltage is incorrect.Repair: The configuration of the wiring between the