FRAME ASSEM. 7J2840 - Caterpillar

Illustration 1 g02404766
Connections of the Lift Lever Position Sensor
This diagnostic code is associated with the Lift Lever Position Sensor. The position sensor is located in the lift lever assembly. The FMI 08 means that the ECM has determined that the signal frequency or the signal pulse width is not within the expected range.Each lever position sensor is supplied system voltage through the right column, fuse F39 in the switched upper fuse panel (10A 146-GY(Grey)). Each sensor is supplied an ECM ground circuit (C214-BK(Black)) connection from the Implement ECM J1-70 contact and the Machine ECM J1-70 contact.The position sensor is a PWM sensor that operates at a frequency of approximately 500 100 Hz. The position sensor sends a PWM input signal to the ECM. The duty cycle of the signal will vary from 10% to 90%. The variations in the duty cycle of the signal follow:
Table 1
Lever Position Acceptable Sensor PWM Duty Cycle (Percent)
Full Forward 7 to 14
Centered 50 4
Full Rearward 85 to 93 The possible conditions that could cause this diagnostic code are:
The sensor has failed.
Intermittent connections or poor connections
The linkage is loose or damaged.
The ECM has failed. This condition is unlikely.Note: Loose or damaged linkage will most likely not cause an FMI 08 diagnostic code, but the linkage should be checked.Note: The correct operating temperature range for the sensor is −40 °C (−40.0 °F) to 75 °C (167.0 °F). When the environment of the cab is at extreme temperatures, an FMI 03 or an FMI 08 the diagnostic code becomes active. Standardize the environment of the cab, in order to keep the sensors operating in the acceptable temperature range. After standardizing the temperature to normal, verify that the CID 0352 FMI 08 diagnostic code is active before performing this procedure.Note: 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, that all connections are secure and that all connections are 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 problem has been corrected.Test Step 1. CHECK THE DUTY CYCLE AND THE SIGNAL FREQUENCY AT THE SENSOR
Turn the key start switch and the disconnect switch to the OFF position.
At the machine harness connector C2 for the control lever assembly, use a 151-6320 Removal Tool to remove the signal wire H710-PK(Pink) and the socket at contact 3 from the harness connector. The connector for the machine harness C2 remains connected to the lever assembly.
At the back of the C2 harness connector, insert 7X-1710 Multimeter Probes along the ground contact 2 and the signal contact at 3.
Turn the disconnect switch and the key start switch to the ON position.
With the lever