Deutz-Fahr 419 – ECU: Camshaft Speed Sensor Signal Faulty

The Engine Control Unit (ECU) has detected that the signal from the camshaft speed sensor is disturbed, implausible, or has an abnormal frequency, pulse width, or period. This means the ECU is receiving an erratic or incorrect signal that does not match the expected pattern from a properly functioning sensor, which can lead to engine performance issues such as hard starting or a complete failure to start.

• Agrofarm 410
• Agrofarm 420
• Agrofarm 430
• Agrofarm 85
• Agrofarm 100
• Agrotron K90
• Agrotron K100
• Agrotron K110
• Agrotron K120
• Agrotron 210
• Agrotron 235
• Agrotron 265

1. 1

   Visually inspect the camshaft sensor to ensure it is properly installed and securely mounted.

2. 2

   Verify the correct distance (air gap) between the sensor tip and the camshaft's pulse wheel (reluctor wheel).

3. 3

   Inspect the pulse wheel for any physical damage, such as bent or missing teeth.

4. 4

   Disconnect the battery and inspect the sensor's electrical connector and harness pins for corrosion, moisture, oil contamination, or damage. Clean with electrical contact cleaner if necessary.

5. 5

   Check the wiring harness for physical damage (chafing, melting, breaks) and verify electrical continuity between the sensor connector and the engine ECU connector (e.g., connector MX1).

6. 6

   Measure the sensor's internal resistance with a multimeter and compare it to the specification in the service manual.

7. 7

   For 3-wire Hall-effect sensors, turn the ignition on (engine off) and verify the correct reference voltage (typically 5V or 12V) and a solid ground connection from the ECU.

8. 8

   While cranking the engine, use a multimeter or oscilloscope to check for a proper signal output (AC voltage for 2-wire sensors, or a pulsing DC square wave for 3-wire sensors).

1. 1

   Prepare machine

   Park the machine on a level surface, ensure it cannot move, and disconnect the negative battery terminal to prevent electrical damage.

2. 2

   Locate and access sensor

   Locate the faulty camshaft position sensor (typically on the cylinder head, near the timing cover, or under the injection pump) and remove any obstructing components like engine covers or air filter housings.

3. 3

   Remove old sensor

   Disconnect the electrical wiring harness from the sensor. Remove the single mounting bolt holding the sensor in place, then gently twist and pull the sensor to remove it from the engine block or timing cover.

4. 4

   Prepare for installation

   Ensure the O-ring from the old sensor has been removed and did not fall into the engine. Lightly lubricate the O-ring on the new sensor with clean engine oil for easier installation.

5. 5

   Install new sensor

   Carefully insert the new sensor into its mounting hole, ensuring it is fully seated.

6. 6

   Secure and reconnect

   Reinstall the mounting bolt and tighten it to the manufacturer's specified torque. Do not overtighten, as this can damage the sensor. Securely plug the electrical connector back onto the new sensor.

7. 7

   Final assembly and testing

   Reinstall any components that were removed for access. Reconnect the negative battery terminal. Start the engine and let it run for several minutes to allow the ECU to recognize the new sensor. The fault code should clear, and the check engine light should turn off.