John Deere 524219.03 – ATC: High Voltage From The Screen Defog Sensor (B143)

The control unit has detected that the voltage at the signal input for the windshield defog sensor (specifically on lead 2003) is too high (typically over 5 volts). This condition means the circuit is likely shorted to a power supply lead, or there is an open circuit/internal interruption between the sensor and the controller. When this code is active, the automatic temperature control is restricted, and the defogging system may fail to activate, compromising cab visibility.

• 6110R
• 6120R
• 6130R
• 6145R
• 6155R
• 6175R
• 6195R
• 6215R
• 6120
• 6220
• 6320
• 6420
• 6820
• 6920
• 6230
• 6330
• 6430
• 8245R
• 8270R
• 8295R
• 8320R
• 8335R
• 8345R

1. 1

   Visually inspect the defog sensor (mounted on the windshield) and its wiring harness for signs of physical damage, dirt, or corrosion.

2. 2

   Inspect the electrical connections at the sensor and the ATC controller. Look for bad, loose, widened, slid-back, or corroded pins.

3. 3

   Use a multimeter to verify the voltage at the defog sensor's signal input (lead 2003). If it reads over 5V, you have a short to power or an open ground.

4. 4

   Test the continuity of the harness between the sensor plug and the ATC module to isolate whether the short/open circuit is in the wiring harness or internal to the sensor itself.

1. 1

   Power Down

   Turn off the machine and disconnect the battery to protect the ATC module during electrical repairs.

2. 2

   Harness Repair

   If your multimeter tests revealed a short to a supply lead or an open connection in lead 2003, locate the damaged section of the wiring harness and repair or replace the affected wires/connectors.

3. 3

   Sensor Replacement

   If the harness tests perfectly, the B143 sensor has failed internally. Carefully pry off or unscrew the plastic defog sensor shield/cover from the windshield. Disconnect the sensor's electrical connector. Remove the faulty sensor from its windshield mount. Install the new sensor, plug in the connector, and snap the protective shield back into place.

4. 4

   System Reset

   Reconnect the battery. Clear the stored ATC 524219.03 fault code from the system using a diagnostic tool or the cab monitor.

5. 5

   Functional Test

   Run the tractor and activate the ClimaTrak defogging system to ensure the code does not return and the system operates normally.