SENSOR-PRESSURE 2641422 - Caterpillar

Illustration 1 g00803344
Schematic of the Transmission Oil Temperature Sensor
Note: If the diagnostic code is only present under certain extreme operating temperatures, the sensor is probably out of specification. Replace the sensor.A CID 0177 FMI 03 is recorded when the ECM reads the voltage of the sensor as above normal.The possible causes of this diagnostic code are listed:
The +8V circuit (wire 799-WH(White)) to the sensor is open.
The return circuit (wire J765-BU(Blue)) is open.
The signal circuit (wire 428-OR(Orange)) is shorted to the + battery.
The signal circuit (wire 428-OR(Orange)) is open or the sensor is disconnected.
The sensor has failed.
The ECM has failed. This is unlikely.The results of this diagnostic code are listed:
A warning (Category 2) that is showing on the monitor
An incorrect reading on the gaugeService Notes: Ensure that the CID 0177 FMI 03 is active. This procedure can cause new diagnostic codes to be recorded. Ignore these created diagnostic codes. When the procedure is completed, clear the created diagnostic codes.Test Step 1. CHECK THE SUPPLY VOLTAGE AT THE SENSOR.
Turn the disconnect switch and the key start switch to the ON position.
Check the voltage at the machine harness connector of the sensor from contact A (sensor supply) to contact B (ground). Do NOT disconnect the sensor. Use the 7X-1710 Cable probes to measure the voltage. Expected Result:The voltage should measure approximately 8 DCV.Results:
OK - The voltage is approximately 8 DCV. The voltage is correct. Proceed to test step 3.
NOT OK - The voltage is not approximately 8 DCV. There is an open in the machine harness or the ECM has failed. It is unlikely that the ECM 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.
Disconnect the sensor from the machine harness.
At the machine harness