BIT-END LH 4T3050 - Caterpillar

Illustration 1 g01620155
Schematic of the "Speed Sensor (Torque Converter Output)"This diagnostic code is recorded when the Transmission/Chassis ECM receives an incorrect signal from the torque converter output speed sensor. When the following conditions exist, the technician may believe that the output sensor for the torque converter has failed.There is no speed from torque converter output but the following conditions are present:
The transmission is in neutral and the "Engine Output Speed Sensor" is over 100 RPM after the engine has started.
The transmission is in a "forward" gear, and any "Transmission Output Speed Sensor" reads above 100 RPM.When the diagnostic code is active, the ECM will be unable to calculate the proper speed ratio. The quality of shifting will be affected.Note: The machine must be moving in order for the ECM to show this failure.Test Step 1. CHECK THE SPEED SENSOR RESISTANCE
Turn the key start switch and the disconnect switch to the OFF position.
Disconnect the machine harness from the speed sensor.
At the connector for the speed sensor, measure the resistance between the two contacts of the connector of the speed sensor.Expected Result:The resistance measurement is between 110 ohms and 200 ohms. Results:
OK - The resistance measurement is between 110 ohms and 200 ohms. The speed sensor has not failed. Proceed to test step 2.
NOT OK - The speed sensor has failed.Repair: Replace the sensor. Adjust the speed sensor properly during the installation. See Testing and Adjusting, "Speed Sensor - Adjust". STOPTest Step 2. CHECK FOR AN OPEN IN THE SPEED SENSOR CIRCUIT
Turn the key start switch and the disconnect switch to the OFF position.
Disconnect the machine harness connector from the sensor. At the machine harness connector, place a jumper wire between contact "1" wire (L911-YL) and the contact "2" wire (L910-PK).
Disconnect the J1 and J2 machine harness connectors from the ECM.
At the harness connectors for the ECM, measure the resistance from the contact J1-5 wire (L911-YL) to contact J1-4 wire (L910-PK).Expected Result:The resistance measurement is less than 5 ohms.Results:
YES - The resistance measurement is less than 5 ohms. The circuit is correct. Proceed to Test Step 3.
NO - The resistance measurement is greater than 5 ohms. There is an open or a bad connection in the circuit.Repair: There is an open circuit or a bad connection in the machine harness. The problem is with wire (L910-PK). Refer to Electrical System Schematic, KENR8916. Examine all of the connectors that are in the circuit. Ensure that the connections are clean and secure. Repair the machine harness or replace the machine harness.STOPTest Step 3. CHECK THE SIGNAL CIRCUIT FOR AN OPEN IN THE MACHINE HARNESS
Place a jumper between the two contacts of the machine harness connector for the speed sensor.
Disconnect connectors J1 and J2 from the machine harness of the ECM.
Measure the resistance from the sensor signal J1-4 wire (L910-PK) to the return contact J1-5 wire (L911-YL) of the machine harness.Expected Result:There should be continuity (less than 5.0 ohms resistance). Results:
OK - The signal circuit in the machine harness is correct. Proceed to test