VALVE GP 6E0629 - Caterpillar

Illustration 1 g03815754
Schematic of the Cab (Recirculation Filter) Air Temperature SensorThis diagnostic code is recorded when the Implement ECM reads the input signal from the Cab Air Temperature Sensor and the voltage is above normal.If the voltage of the sensor input circuit is greater than 4.95 VDC, an FMI 03 diagnostic code will be activated.Possible causes of the diagnostic code are listed:
There is an open in the sensor circuit.
The signal circuit is shorted to another circuit.
The sensor has failed.
The ECM has failed. This condition is unlikely.Poor connections may be the cause of a problem in an electrical circuit.
Verify that all connections in the circuit are clean. Verify that all connections in the circuit are secure. Verify that all connections in the circuit are 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 Auto Temperature Control feature will not work properly.Note: Ensure that CID 0779 FMI 03 diagnostic code is active. This procedure may cause new diagnostic codes to be recorded. Ignore these created diagnostic codes. When the procedure is completed, clear the created diagnostic codes.Note: A digital multimeter will be required for the measurements in this procedure.Test Step 1. CHECK FOR AN OPEN IN THE RETURN CIRCUIT
Turn the key start switch and the disconnect switch to the OFF position.
Locate the sensor and disconnect the machine harness from the sensor.
At the machine harness connector for the sensor, place a jumper wire from contact 2 (wire 299-BK) to frame ground.Note: Ensure that the frame ground contact point is clean and free of paint, oil, dirt, and any other debris.
Disconnect the machine harness connector J1 from the Implement ECM.
At the J1 machine harness connector for the ECM, measure the resistance from contact J1-70 (wire 299-BK) to frame ground.Note: Ensure that the frame ground contact point is clean and free of paint, oil, dirt, and any other debris.Expected Result:The resistance measurement is less than 5 ohms.Results:
OK - The resistance measurement is less than 5 ohms. Proceed to test step 2.
NOT OK - The resistance measurement is