PLATE-THRUST-YM 3256169 - Caterpillar

Illustration 1 g00789954
Schematic of the Position Sensor (Forward/Neutral/Reverse) Circuit of the JoystickThis diagnostic code is recorded when the ECM reads the duty cycle of the sensor as being out of range.Note: This diagnostic code is usually an intermittent condition. The diagnostic code may be active or the diagnostic code may not be active.The output frequency of the position sensor is approximately 500 hertz. The duty cycle of the signal changes as the position sensor moves. The duty cycle varies from 29% when the joystick is in the FORWARD position. The duty cycle varies to 71% when the joystick is in the REVERSE position. The duty cycle is approximately 50% when the joystick is in the NEUTRAL position.The possible causes of this condition are listed:
The signal circuit is shorted to the +battery circuit or shorted to ground intermittently.
The signal circuit is open intermittently or the sensor is disconnected.
The sensor may have failed.Note: This procedure can cause new diagnostic codes to be recorded. Ignore these created diagnostic codes. When the procedure is completed, clear the created diagnostic codes.System Response:When this diagnostic code occurs, the action lamp and the action alarm is ON. The diagnostic code will cause the joystick to stop functioning. The machine will decelerate to a stop.Test Step 1. CHECK THE SIGNAL CIRCUIT FOR AN OPEN.
Turn the key start switch and the disconnect switch to the OFF position.
The sensor remains disconnected from the machine harness.
At the machine harness connector for the sensor, install a jumper wire from contact 3 (wire F853-BR) to contact 2 (wire F750-YL).
Disconnect the J1 and J2 machine harness connectors from the ECM.
At the machine harness connector J1, measure the resistance from contact J1-2 (wire F853-BR) to J1-9 (wire F750-YL).Expected Result:The resistance should be less than 5.0 ohms.Results:
OK - The resistance is less than 5.0 ohms. The machine harness is correct. Proceed to test step 2.
NOT OK - The resistance that is measured is greater than 5000 ohms. Repair: There is an open in the machine harness. Repair the machine harness or replace the machine harness. Verify that the problem has been corrected.STOPTest Step 2. CHECK THE SIGNAL CIRCUIT FOR A SHORT.
The key start switch and the disconnect switch remain in the OFF position.
The machine harness remains disconnected from the sensor.
Remove the jumper wire from the previous test step.
At the machine harness connectors J1 and J2, measure the resistance from contacts J1-2 (wire F853-BR) to all other J1 and J2 contacts.Expected Result:The resistance should be greater than 5000 ohms for each measurement.Results:
YES - The machine harness is correct. Proceed to test step 3.
NO - The resistance is not correct.Repair: There is a short in the machine harness. The short is between the circuit with the low resistance measurement and wire (F853-BR). Repair the harness or replace the harness.STOPTest Step 3. CHECK IF THE DIAGNOSTIC CODE REMAINS.
Clean all contacts of the harness connector.
Reconnect all harness connectors.
Turn the disconnect switch and the key start switch to the ON position.
Clear all inactive diagnostic codes.
Operate the machine.
Check the status of