Case IH 3091 (DTC 4112) - ECU – Engine Control Unit (ECU / ECM): Camshaft speed sensor pattern is not plausible

The control module evaluates the signals received from the camshaft and crankshaft speed sensors for angle, speed determination, signal plausibility, and quality. This code triggers when the module determines that the camshaft signal does not match the correct pattern (e.g., edge distance, level) or not all expected camshaft edges are detected during engine revolution.

• MAXXUM T4E
• 240 Series Axial-Flow Combines
• Puma Series Tractors
• Steiger Series Tractors
• Magnum Series Tractors
• Farmall Series Tractors
• Maxxum Series Tractors

1. 1

   Check if any other error codes are displayed on the service monitor. If other codes are present, diagnose them first.

2. 2

   Verify that the tractor's battery power supply has not been connected to an external power supply. If an external power supply is connected, disconnect it and test the system for normal operation.

3. 3

   Visually inspect the relevant wiring harnesses and connectors between the camshaft speed sensor and the ECU. Look for damage, bent or dislocated pins, corroded terminals, or broken wires.

4. 4

   Verify that the connectors are fully seated and installed. Flex the harnesses involved to reveal any intermittent breaks or shorts.

5. 5

   Check the ECU (A-095) for the appropriate software version to see if a re-flash is necessary.

1. 1

   Resolve related faults

   Resolve any active faults related to the fuel system or power supply first, as these can sometimes cause erratic sensor readings.

2. 2

   Repair wiring and connectors

   Repair or replace any damaged wiring or connectors found during the visual inspection.

3. 3

   Replace camshaft speed sensor

   If the wiring is intact, the external power supply is disconnected, and the fault has not been resolved, remove and replace the camshaft speed sensor.

4. 4

   Re-flash ECU

   If the fault persists after sensor replacement, re-flash the ECU with the latest software.

5. 5

   Verify repair

   Clear the fault codes and return the machine to service to verify the repair.