RING-LOAD 8E9645 - Caterpillar

Illustration 1 g00778763
Schematic of the Position Sensor for the Decelerator Pedal Note: The sensor does not connect directly to frame ground. The sensor connects to the return circuit of the ECM. The ECM internally connects the return wire to frame ground.This diagnostic code is recorded when the ECM reads the sensor signal as being below normal. There is a short to ground. Note: The sensor is probably out of specification, if the diagnostic code is only present under certain extreme operating conditions such as pedal "full-up" or pedal "full-down". Replace the sensor and calibrate the new sensor. SeeTesting and Adjusting, "Position Sensor (Deceleration Pedal) - Calibrate" for more information.The possible causes of this diagnostic code are listed:
The +battery circuit (wire 497-BU) from the electrical system to the sensor is open.
The signal circuit is shorted to ground.
The sensor has failed.
The ECM has failed. This is unlikely. Note: Ensure that CID 1693 FMI 04 is on hold and that the diagnostic indicator is illuminated. Note: The following test procedure may create other diagnostic codes. Ignore these created diagnostic codes and clear the diagnostic codes when the original diagnostic code has been corrected.System Response:When this diagnostic code occurs, the action lamp is ON. The diagnostic code will cause the underspeed performance to be affected.Test Step 1. CHECK THE SENSOR.
Turn the disconnect switch and the key start switch to the ON position.
Ensure that the diagnostic code is active.
Observe the status of the diagnostic code. Then, disconnect the sensor from the machine harness.Expected Result:The diagnostic code will remain active if the sensor is not the cause of the diagnostic code. The sensor is the cause of the diagnostic code if the diagnostic code is NO longer active.Results:
OK - The diagnostic code remains active. The sensor has not failed. The machine harness may have failed or the ECM may have failed. Proceed to test step 2.
NOT OK - The diagnostic code is NO longer active. The machine harness and the ECM are operating properly.Repair: The sensor has failed. Replace the sensor. Calibrate the sensor. See Testing and Adjusting, "Position Sensor (Deceleration Pedal) - Calibrate" for more information. Verify that the new sensor corrects the problem.STOPTest Step 2. CHECK THE SIGNAL CIRCUIT FOR A SHORT TO GROUND.
The sensor remains disconnected from the machine harness.
Turn the key start switch and the disconnect switch to the OFF position.
Disconnect the J1 and J2 machine harness connector from the ECM.
At the J1 machine harness connector, measure the resistance from contact J1-24 (wire M730-YL) to all contacts that are used in the machine harness connectors for the ECM.Expected Result:The resistance is greater than 5000 ohms for each measurement.Results:
OK - The resistance is greater than 5000 ohms for each measurement. Proceed to Test Step 3.
NOT OK - One or more of the resistance measurements is NOT correct.Repair: The machine harness has failed. There is a short in the machine harness between the signal circuit and the circuit with the low resistance measurement. Repair the machine harness or replace the machine harness.STOPTest