STEP GP 3586840 - Caterpillar

Illustration 1 g01251041
Schematic of the Primary and Secondary Keypad ShiftersThis diagnostic trouble code is associated with the gear lever selector sensor(s). The FMI 02 means that the ECU has determined that the voltage of the circuit for the position sensor is below normal. The possible causes of this diagnostic trouble code are listed below:
The signal circuit for the sensor is shorted to ground.
The sensor has failed.
The ECU has failed. This is unlikely. Note: The following test procedure may create other diagnostic trouble codes. Ignore these created diagnostic trouble codes and clear the diagnostic trouble codes when the original diagnostic trouble code has been corrected. Ensure that the diagnostic trouble code of CID 0702 FMI 02 is active before performing this procedure. Note: Use a digital multimeter for the measurements in this procedure.Test Step 1. VERIFY SOFTWARE VERSIONNote: From SIS or the latest release of the CD for SIS check and record the latest software version for the machine electronic controls.
Verify the transmission ECU has the latest software version loaded.
Verify that the valve ECU's have the latest software loaded.Expected Result:All of the software is up to date.Results:
OK - All of the software is up to date. Proceed to Test Step 2.
NOT OK - There is a more recent software release available.Repair: Flash all controls with the latest software release. Refer to Testing and Adjusting, "Electronic Control Unit - Flash Program".STOPTest Step 2. CHECK THE HARNESS.
Turn the key start switch to the OFF position.
Inspect the harness.
Check for the proper mating.
Check the exposed wires for nicks and abrasions.
Check for moisture, dirt, or corrosion.
Check the pin/socket for a proper fit.
Disconnect the machine harness connectors from the transmission ECU.
At the machine harness connector, measure the resistance from connector contact 1 (wire K900-YL) to J2-67 (wire K900-YL) of the transmission ECU. Expected Result:The resistance should be less than 5 ohms.Results:
OK - The resistance is less than 5 ohms. The machine harness is correct. Proceed to test step 3.
NOT OK - The resistance is greater than 5 ohms. There is an open in the machine harness. The open is between the modules for the signal (wire K900-YL).Repair: Repair the machine harness or replace the machine harness.STOPTest Step 3. CHECK IF THE DIAGNOSTIC TROUBLE CODE IS STILL ACTIVE.
Inspect the harness connectors and clean the contacts of the harness connectors and check the wires for damage to the insulation that is caused by excessive heat, battery acid, or chafing.
Perform a 45 N (10 lb) pull test on each of the wires that are associated with the circuit.
Reconnect all harness connectors making sure that the connectors are fully seated and the clips for each connector are completely fastened.
Turn the disconnect switch and the key start switch to the ON position.
Operate the machine.
Determine if the CID 0702 FMI 02 is active.Expected Result:The CID 0702 FMI 02 is active.Results:
YES - The CID 0702 FMI 02 is active. The problem has not been corrected.Repair: Check the circuit again. Use the Caterpillar Electronic Technician (ET) service tool, if available, in order to perform