BUCKET GP-MULTIPURPOSE 3620900 - Caterpillar

Illustration 1 g01152367
Schematic of circuit for the left and right movement of Left joystickThis diagnostic code is associated with the circuit of the left and right movement of the Left joystick. The FMI 08 means that the machine ECM determined that the signal frequency or the signal pulse width is not in the expected range. The possible causes of this diagnostic code are listed:
The control for the left joystick has failed.
The ECM has failed.
Intermittent connections or poor connections
There is electromagnetic interference.
Mechanical devices that are loose This failure may result in erratic operation of the machine.Test Step 1. CHECK THE SUPPLY VOLTAGE (+12 DCV).
Turn the key start switch and the disconnect switch to the OFF position.
Disconnect the machine harness connector from the left joystick.
Turn the disconnect switch and the key start switch to the ON position.
At the machine harness connector for the left joystick, measure the voltage (DCV) between contact 1 (wire M947-OR) and frame ground.Expected Result:The voltage is 12 0.5 DCV for both measurements.Results:
OK - The voltage is 12 0.5 DCV for both measurements. The voltage is correct. Proceed to test step 2.
NOT OK - The voltage is NOT 12 0.5 DCV for both measurements. The voltage is not correct. The machine ECM has failed or the harness has failed. It is unlikely that an ECM has failed. Verify the harness.Repair: If the harness is correct, replace the ECM. See Testing And Adjusting, "Electronic Control Module (ECM) - Replace". Stop.Test Step 2. VERIFY THE GROUND OF THE ELECTRONIC CONTROL MODULE.
Turn the key start switch and the disconnect switch to the OFF position.
Disconnect the machine harness connector J1 and J2 of the machine ECM.
At the machine harness connector J2, measure the resistance between contact J2-2 (wire 235-BK) and frame ground. Expected Result:The resistance is less than 5 ohms. Results:
OK - The resistance is less than 5 ohms. The circuit resistance is correct. Proceed to test step 3.
NOT OK - The resistance is greater than 5 ohms. The circuit resistance is not correct. The harness is open.Repair: Repair the machine harness or replace the machine harness. Stop.Test Step 3. VERIFY THE GROUND CIRCUIT OF THE LEFT JOYSTICK.
At the machine harness connector for the left joystick, place a jumper between contact 2 (wire M948-BR) and frame ground.
At the machine harness connector J1, measure the resistance between the contact J1-9 (wire M948-BR) and frame ground.Expected Result:The resistance is less than 5 ohms. Results:
OK - The resistance is less than 5 ohms. The circuit resistance is correct. Proceed to test step 4.
NOT OK - The resistance is greater than 5 ohms. The circuit resistance is not correct. The harness is open.Repair: Repair the machine harness or replace the machine harness. Stop.Test Step 4. CHECK THE SIGNAL CIRCUIT OF THE LEFT JOYSTICK.
Remove the jumper that was placed in the previous test.
At the machine harness connector of the left joystick, place a jumper between contact 3 (wire