MANIFOLD GP-CONTROL 2316285 - Caterpillar

Illustration 1 g01248577
Schematic of the Right Joystick Thumbwheel Modulation controlThis diagnostic code is associated with the Right Joystick Thumbwheel Modulation control. The FMI 08 means that the ECM has determined that the signal frequency or the signal pulse width is not within the expected range.The Thumbwheel Modulation control has an output frequency of approximately 500 Hz. The duty cycle of the signal changes as the Thumbwheel position is changed. The duty cycle varies from approximately 19% at the minimum position to approximately 77% at the maximum position. The duty cycle is approximately 48% at the center position.The possible causes of this diagnostic code are listed:
The Thumbwheel Modulation control has failed.
Intermittent connections or poor connections
Mechanical devices are loose.
The ECM has failed. This is unlikely.System Response:When this diagnostic code occurs, there is no warning on the monitor. The function for the work tool that is controlled by the Thumbwheel Modulation control will not function.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 1658 FMI 08 is active before performing this procedure.Note: Use the 146-4080 Digital Multimeter for the measurements in this procedure. Test Step 1. CHECK FOR POWER AT THE THUMBWHEEL MODULATION CONTROL.
Do not disconnect the harness connector from the joystick.
Turn the key start switch and the disconnect switch to the ON position.
At the back of the harness connector for the joystick, insert a 7X-1710 Multimeter Probe along the voltage supply wire E472-GN (contact A).
Measure the voltage from contact A (wire E472-GN) to frame ground.Expected Result:The voltage is approximately 8 DCV.Results:
OK - The voltage is approximately 8 DCV. Proceed to Test Step 2.
NOT OK - The voltage is not approximately 8 DCV. The circuit is open. Repair: Repair the machine harness or replace the machine harness.STOPTest Step 2. CHECK THE SIGNAL CIRCUIT OF THE THUMBWHEEL MODULATION CONTROL FOR THE CORRECT DUTY CYCLE.
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 A (wire E472-GN) and insert the probe along the signal wire E473-GY (contact C).
At the back of the harness connector for the sensor, insert a 7X-1710 Multimeter Probe along the ground wire 235-BK (contact B).
Turn the disconnect switch and the key start switch to the ON position.
Monitor the duty cycle of the Thumbwheel Modulation control with the 146-4080 Digital Multimeter .
Without disconnecting the joystick or the hardware that is associated with the joystick from the machine, move the Thumbwheel through the entire range of motion.Note: On some machines, it may be necessary to start the engine in order to move the Thumbwheel through the entire range of motion.Expected Result:The value of the Thumbwheel duty cycle responds in the manner that is described at the begining of this procedure.Results:
OK - The value of the Thumbwheel duty cycle responds correctly. The Thumbwheel Modulation control is operating