PISTON & ROD GP 1352851 - Caterpillar

Illustration 1 g01529068
Schematic of the "Position Sensor (Bucket Cylinder)"This diagnostic code is associated with the "bucket cylinder" position sensor. This diagnostic code is recorded when the ECM reads the signal from the sensor and the ECM determines that the signal is erratic, intermittent, or incorrect.The possible causes of this diagnostic code are listed below:
Wire (H902-YL) is shorted to the ground circuit while the machine is in operation.
Wire (H902-YL) is shorted to the +battery.
An open circuit exists.
The ECM has failed. This is unlikely.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 1956 FMI 02 is active before performing this procedure.Note: Use the 146-4080 Digital Multimeter for the measurements in this procedure.System Response:The diagnostic code of CID 1956 FMI 02 will be logged in the internal memory of the ECM and a level 2 warning is generated.Test Step 1. VERIFY THAT THE VERSION OF THE SOFTWARE IS CORRECT Note: Use SIS (or the latest release of the CD for SIS) in order to check and record the version of the software that is the latest for the electronic controls of the machine.
Verify that the Machine ECM is loaded with the latest version of the software.
Verify that the latest version of the software is loaded for the "Valve" ECM modules.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 release of the software that is available.Repair: Flash all controls with the latest software release. Refer to Troubleshooting, "Electronic Control Module (ECM) - 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 machine ECM.
At the machine harness connector, measure the resistance from connector contact 3 (wire H902-YL) to J2-17 (wire H902-YL) of the machine ECM. 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 H902-YL).Repair: Repair the machine harness or replace the machine harness.STOPTest Step 3. CHECK IF THE DIAGNOSTIC CODE REMAINS.
Clean the contacts of the harness connectors.
Reconnect all harness connectors.
Observe the status of the diagnostic code.
Operate the machine.
Observe the status of the diagnostic code.Expected Result:The diagnostic code is NO longer active.Results:
YES