LOCK 1S4259 - Caterpillar

Illustration 1 g02359724
Schematic of the Left Hand joystick
This diagnostic code is associated with the power train speed range control position sensor. The FMI 08 diagnostic means that the ECM has determined that the signal frequency or the signal pulse width is not within the expected range. The sensor is a PWM sensor that operates at a frequency of approximately 500 Hz. The sensor has an operating duty cycle of 15% to 85%. The possible causes of this diagnostic code are listed below:
The sensor has failed.
Intermittent connections or poor connections
Mechanical devices are loose.
The ECM has failed. The ECM failing is unlikely.Before performing this procedure, inspect the harness connectors that are involved in the circuit. Poor connections can often be the cause of a problem in an electrical circuit. Verify that all connections in the circuit are clean, secure and in good condition. If a problem with a connection is found, correct the problem and verify that this diagnostic code is active before performing this procedure.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. Ensure that the diagnostic code of CID 2500 FMI 08 is active before performing this procedure.Note: Use a Digital Multimeter for the measurements in this procedure. System Response:A level 1 warning will be generated. Functionality is lost and the ECM cannot increase or decrease the desired speed. Other sensors can aid in reducting machine speed such as brake pedal.Test Step 1. CHECK FOR POWER AT THE SENSOR.
Do not disconnect the harness connector from the sensor.
At the back of the harness connector for the sensor, insert a 7X-1710 Multimeter Probe along contact 1 (wire J850-WH(White)) for the voltage supply.
At the back of the harness connector for the sensor, insert a 7X-1710 Multimeter Probe along contact 2 (wire J764-BR(Brown)) for the ground.
Turn the key start switch and the disconnect switch to the ON position.
Measure the voltage from contact 1 (wire J850-WH(White)) to contact 2 (wire J764-BR(Brown)). Expected Result:The voltage is 8 0.5 DCV.Results:
OK - The voltage is 8 0.5 DCV. Proceed to Test Step 3.
NOT OK - The voltage is not 8 0.5 DCV. The circuit is open. Repair: Repair the machine harness or replace the machine harness.STOPTest Step 2. CHECK THE SIGNAL CIRCUIT OF THE SENSOR.
Turn the key start switch and the disconnect switch to the OFF position.
At the back of the harness connector for the sensor, remove the 7X-1710 Multimeter Probe from contact 1 and insert the probe along the signal wire contact 1 (wire J764-WH(White)).
The other 7X-1710 Multimeter Probe remains at the ground wire contact 2 (wire J764-BR(Brown)).
Turn the disconnect switch and the key start switch to the ON position.
Monitor the signal of the sensor with the multimeter.
Without disconnecting the sensor or the hardware that is associated with the sensor from the machine, take the sensor through the full operating range of the sensor. Expected Result:The sensor signal responds