Fendt 1.2.A8 – EDC (Electronic Diesel Control) Module: Fault in barometric pressure sensor

The engine control unit has detected an incorrect or implausible value from the barometric (atmospheric) air pressure sensor. The system defaults to a standard pre-programmed pressure value, allowing normal operation but potentially reducing fuel efficiency or power at varying altitudes.

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1. 1

   Visually inspect the barometric/manifold air pressure sensor and wiring harness for chafing, breaks, or melted insulation.

2. 2

   Disconnect the sensor and check the pins for corrosion, moisture, or loose connections.

3. 3

   Verify that the sensor is receiving the correct reference voltage (typically 5V) and has a solid ground connection from the EDC module.

4. 4

   Use FENDIAS or Serdia diagnostic software to read live data from the barometric pressure sensor; a static, out-of-range, or zero reading indicates internal failure.

1. 1

   Power Down

   Turn off the tractor, remove the key, and disconnect the negative battery terminal to prevent electrical spikes.

2. 2

   Locate the Sensor

   Depending on the specific engine (e.g., Deutz or MAN), the sensor will be located either directly on the intake manifold (acting as a combined manifold absolute pressure/barometric sensor) or mounted near the EDC module.

3. 3

   Remove the Sensor

   Depress the locking tab on the electrical pigtail and disconnect it. Remove the retaining bolts or unscrew the sensor from its mounting port.

4. 4

   Install the New Sensor

   Seat the new OEM sensor into the port. If it uses an O-ring, ensure it is lightly lubricated to prevent tearing. Tighten the retaining hardware to the manufacturer's torque specification.

5. 5

   Reconnect

   Plug the electrical connector back in until it clicks securely. Reconnect the battery.

6. 6

   Clear Codes

   Connect a diagnostic tool to the tractor's diagnostic port, clear the 1.2.A8 / A021 fault code from the EDC memory, and run the engine to verify the code does not return.