PLATE-END 5087417 - Caterpillar

Illustration 1 g01442746
Schematic of the Transmission Lock SwitchThis diagnostic code is associated with the Transmission Lock Switch. This diagnostic code is recorded when the ECM reads the signal from the switch and the ECM determines that the signal is erratic, intermittent, or incorrect.The possible causes of this diagnostic code are listed:
Wire (C720-BU) is shorted to the ground circuit while the machine is in operation.
Wire (C720-BU) is shorted to the +battery.
An open circuit exists.
The Transmission Lock Switch has failed.
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 0626 FMI 02 is active before performing this procedure.Note: Use the 146-4080 Digital Multimeter for the measurements in 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, secure, and 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. System Response:The machine response is listed:
Machine functions will be limited.Note: Before performing the following Test Steps, check that the speed switch is securely mounted. If the mounting of the speed switch is correct and the CID 0626 FMI 02 code is active, proceed to Test Step 1.Test Step 1. VERIFY THE 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 Machine ECM has the latest software version loaded.Expected Result:The software is up to date.Results:
OK - The software is up to date. Proceed to Test Step 2.
NOT OK - A more recent software release is available.Repair: Flash the ECM with the latest software release. Refer to Testing and Adjusting, "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 4 (wire C720-BU) to J2-47 (wire C720-BU) 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 in the signal wire (C720-BU).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