88512 Mercury CLAMP

Illustration 1 g01239089
Schematic for throttle position sensorTest Step 1. Inspect the Electrical Connectors and the Wiring
Remove the electrical power from the ECM.
Illustration 2 g01141049
J1/P1 ECM connector
Thoroughly inspect the J1/P1 ECM connector and the connector for the throttle position sensor. Inspect the machine connector for damage or corrosion. Refer to the diagnostic functional test Troubleshooting, "Electrical Connectors - Inspect" for details.
Illustration 3 g01143213
P1 ECM connector (P1-4) 8 VDC supply (P1-5) Digital return (P1-66) Throttle position
Illustration 4 g01239091
Terminals on the machine connector (Terminal 21) Throttle position (Terminal 23) 8 VDC supply (Terminal 17) Digital return
Illustration 5 g01159881
J403/P403 for the throttle position sensor (A) 8 V supply (B) Digital return (C) Throttle position
Perform a 45 N (10 lb) pull test on each of the wires in the circuit.
Check the allen head screw from each ECM connector for the proper torque. Refer to the diagnostic functional test Troubleshooting, "Electrical Connectors - Inspect" for the correct torque value.
Check the harness and the wiring for abrasion and for pinch points.Expected Result:All of the connectors, pins and sockets are completely coupled and/or inserted and the harness and wiring are free of corrosion, of abrasion and of pinch points.Results:
OK - The harness and connectors appear to be OK. Proceed to Test Step 2.
Not OK - The connectors and/or wiring are not OK.Repair: Repair the connectors or wiring and/or replace the connectors or wiring. Ensure that all of the seals are properly in place and ensure that the connectors are completely coupled.Verify that the repair eliminates the problem.STOPTest Step 2. Inspect the Throttle Pedal Assembly
Inspect the throttle pedal assembly for components that are loose, bent, missing, or worn.
Slowly depress the pedal and release the pedal.Expected Result:The throttle pedal assembly operates smoothly without excessive drag. The pedal springs back smoothly to the low idle position without assistance.Results:
OK - The throttle pedal assembly functions properly. Proceed to Test Step 3.
Not OK - The throttle pedal assembly is in poor repair.Repair: Repair the throttle pedal assembly or replace the throttle pedal assembly, as required.STOPTest Step 3. Check the Status for "Throttle Position"
Connect the Caterpillar Electronic Technician (ET) to the service tool connector.
Restore the electrical power to the ECM.
Observe the status for "Throttle Position" on Cat ET while you operate the throttle pedal through the entire range of travel.Expected Result:The status is zero percent when the throttle pedal is released. The status progressively increases to 100 percent when the throttle pedal is fully depressed.Results:
OK - The throttle position sensor is working properly.Repair: There may be an intermittent electrical problem with the harness or the connectors. Refer to the diagnostic functional test Troubleshooting, "Electrical Connectors - Inspect" if the problem is intermittent.STOP
Not OK - The throttle position that is displayed on Cat ET does not correspond to the movement of the throttle pedal. Proceed to Test Step 4.Test Step 4. Check the Supply Voltage at the Sensor
Disconnect the connector for the throttle position sensor.
Restore the electrical power to the ECM.
Measure the voltage across terminal A (8 V supply) and terminal B (digital return) on the harness side of the connector.
Remove the electrical power from the ECM.Expected Result:The supply voltage measures 8.0 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 5.
Not OK - The voltage is not correct at the sensor connector. The sensor is not receiving the correct supply voltage. Proceed to Test Step 7.Test Step 5. Check the Signal Frequency and the Duty Cycle at the Sensor
Install a 7X-6370 Adapter Cable As (3-PIN BREAKOUT) at the connector for the throttle position sensor.
Remove the signal wire from terminal C of the connector for the throttle position sensor. Remove the wire from the harness side of the connector.
Restore the electrical power to the ECM.
Measure the frequency and the duty cycle between terminal B (digital return) and terminal C (throttle position) at the 7X-6370 Adapter Cable As (3-PIN BREAKOUT) while you operate the throttle pedal.
Remove the electrical power from the ECM.
Remove the breakout harness. Restore the wires to the original configuration.Expected Result:The frequency is between 150 and 1000 Hz. The duty cycle is between 7 and 95 percent.Results:
OK - The frequency and the duty cycle are within specifications for the entire range of the pedal. The sensor is producing a valid signal. Proceed to Test Step 6.
Not OK - The frequency and the duty cycle are not within specifications.Repair: The sensor is not producing a valid s