Case IH 3093 (F-636-31) – Engine ECU (Engine Controller): Compared camshaft and crankshaft speed sensor values are not plausible

The engine control system has detected that the timing signals coming from the camshaft speed sensor and the crankshaft speed sensor are out of sync, or the offset between their readings exceeds the allowable programmed limits.

• VESTRUM CVX
• Magnum 235
• Magnum 315
• Magnum 340
• Steiger 350 to 600
• Farmall 40
• Farmall 45
• Farmall 50
• Farmall 85C
• Farmall 95U
• Farmall 105U
• Farmall 115U
• Farmall 115C
• Maxxum 100
• Maxxum 110
• Maxxum 115
• Maxxum 120
• Maxxum 125
• Maxxum 130
• Maxxum 135
• Maxxum 140
• Maxxum 145
• Maxxum 150
• Puma 130
• Puma 200
• Puma 230

1. 1

   Check for related active faults: If any other sensor-specific error codes are displayed (such as 3088/3089 or 3090/3091/3095), diagnose and resolve those first before returning to 3093.

2. 2

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

3. 3

   Evaluate raw signals: Use an electronic service tool to evaluate the raw signals coming from both the camshaft and crankshaft sensors.

4. 4

   Inspect wiring and installation: Check the wiring harnesses for short circuits to ground or open circuits. Verify the physical installation of both sensors.

5. 5

   Inspect signal wheels: Check the correct positions and physical condition of the camshaft signal wheel and the crankshaft signal wheel (flywheel teeth).

1. 1

   Preparation

   Park the tractor on a flat surface, turn off the engine, and set the parking brake.

2. 2

   Harness Inspection

   Locate the engine wiring harness routing to the camshaft and crankshaft sensors. Inspect the harness for chafing, melted wires, or loose connections.

3. 3

   Sensor Removal & Inspection

   Remove the camshaft and crankshaft speed sensors. Inspect the sensor tips for physical damage or metallic debris buildup.

4. 4

   Signal Wheel Check

   Look through the sensor mounting holes to inspect the tone rings/signal wheels for damaged, bent, or missing teeth.

5. 5

   Sensor Replacement

   If the wiring is intact but the raw signals evaluated during diagnostics are erratic or missing, replace the faulty sensor(s).

6. 6

   Installation

   Install the new sensors into the engine block/timing cover. Ensure the mounting surfaces are clean so the sensors seat at the correct depth (maintaining the factory air gap, which is typically around 0.5-2mm depending on the engine).

7. 7

   Clear and Test

   Reconnect the wiring harness, clear the fault codes using a diagnostic tool, and run the engine to verify the repair.