Case IH 3091 (F-636-02) – Engine Control Unit (ECU A-095): Camshaft speed sensor pattern is not plausible.

The Engine Control Unit is receiving an erratic, intermittent, or incorrect signal pattern from the camshaft speed/position sensor. The ECU relies on this sensor (often compared against the crankshaft speed sensor) to determine engine timing and position. When the values between the camshaft and crankshaft sensors do not align plausibly, this code is triggered.

• VESTRUM CVX
• 240 Series Combines
• Farmall series (40, 45, 50, 85C, 95C, 105C, 115C)
• Magnum / MX series (MX210, MX230, MX255, MX285)
• Puma series
• Maxxum series
• Patriot series (Patriot 4350)

1. 1

   Check the Engine ECU (A-095) for the appropriate software version and update if a newer version is available to address sensor logic

2. 2

   Visually inspect the camshaft sensor wiring harnesses and connectors for physical damage, bent or dislocated pins, corroded terminals, or broken wires

3. 3

   Verify that the sensor connectors are fully seated and locked into place

4. 4

   Perform a wiggle test by flexing the involved wiring harnesses while monitoring the sensor data to reveal any intermittent breaks or short circuits

1. 1

   Resolve Wiring Issues

   If the diagnostic checks reveal damaged wiring or corroded pins, repair the harness or replace the connector pigtail.

2. 2

   Test the Machine

   If a harness repair or ECU re-flash was performed, clear the fault codes and return the machine to service to see if the code returns.

3. 3

   Locate the Sensor

   If the code persists, the camshaft speed sensor itself is likely faulty. Locate the sensor on the engine block/cylinder head (location varies slightly depending on the specific FPT/Iveco engine model).

4. 4

   Remove the Sensor

   Disconnect the electrical connector. Remove the retaining fastener (typically an M6 x 20mm flange bolt). Pull the sensor straight out of its mounting bore.

5. 5

   Install the New Sensor

   Lubricate the O-ring on the new sensor (if applicable) and press it into the bore. Secure it with the retaining bolt.

6. 6

   Reconnect and Clear

   Reconnect the electrical harness. Turn the key on, clear the inactive 3091 fault code via the diagnostic display, and start the engine to verify the repair.