ROD 5K1743 - Caterpillar

Illustration 1 g01245812
Schematic of the torque converter oil temperature sensorThis diagnostic trouble code is associated with the torque converter oil temperature sensor. This diagnostic trouble code is recorded when the ECU reads the voltage from the hydraulic oil temperature sensor as being above normal.Possible causes of the diagnostic trouble code is listed:
The supply circuit to the sensor is open.
The return circuit is open.
The signal circuit is shorted to the +battery.
The signal circuit is open or the sensor is disconnected.
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 these diagnostic trouble codes when the original diagnostic trouble code has been corrected. Ensure that the diagnostic trouble code of SPN 3823 FMI 3 is active before performing this procedure.Note: Use a digital multimeter for the measurements in this procedure.Test Step 1. CHECK THE VOLTAGE AT THE SENSOR.
Turn the disconnect switch and the key start switch to the ON position.
Disconnect the sensor from the machine harness.
At the machine harness connector for the sensor, measure the voltage between contact 1 (wire 407-PK) and contact 2 (wire 202-BK).Expected Result:The voltage is approximately 5 VDC.Results:
OK - The voltage is approximately 5 VDC. Proceed to test step 5.
NOT OK - The voltage is not approximately 5 VDC. Repair: There is a problem with the machine harness or the ECU has failed. It is unlikely that the ECU has failed. Proceed to test step 2.Test Step 2. CHECK FOR AN OPEN IN THE SUPPLY CIRCUIT.
The key start switch and the disconnect switch remain in the ON position.
The sensor remains disconnected from the machine harness.
At the machine harness connector for the sensor, measure the voltage from contact 1 (wire 407-PK) to ground.Expected Result:The voltage is approximately 5 VDC.Results:
OK - The voltage measurement is approximately 5 VDC. Proceed to test step 3.
NOT OK - The voltage does not measure approximately 5 DC.Repair: The supply circuit is not correct. Repair the circuit or replace the circuit.STOPTest Step 3. CHECK FOR AN OPEN IN THE RETURN CIRCUIT.
Turn the disconnect switch and the key start switch to the OFF position.
The sensor remains disconnected from the machine harness.
Disconnect the machine harness connector J1 from the ECU.
At the machine harness connector for the sensor, install a jumper wire from contact 2 (wire 202-BK) to ground.
At the machine harness connector for the ECU, measure the resistance from contact J1-21 (wire 202-BK) to ground.Expected Result:The resistance measurement is less than 5000 ohms.Results:
OK - The resistance measurement is less than 5000 ohms. The harness is correct.Repair: The sensor has failed. Check the sensor. Proceed to Test Step 4.
NOT OK - The resistance that is measured is not correct.Repair: There is an open in the machine harness. The open is in the return circuit with the high resistance measurement. Repair the harness or replace the harness. Proceed to Test Step 5.Test Step 4. CHECK THE SENSOR.
Turn the disconnect switch and the key start switch to the ON position. Do