Kubota P0336 – Engine Control Unit (ECU) / Engine Control Module (ECM): Crank Input Signal Noise

The control module detects electrical noise or an irregular crank pattern (more than 3 crank re-synchronization events in less than 800 milliseconds). This is often triggered by a sudden drop in engine RPM when the engine is bogged down or stalled under a heavy load.

• L3301
• L3901
• L4701
• L3560
• Grand L60 series
• MX series
• M62
• WG1605-E3
• D1105-E3B
• WG-972

1. 1

   Verify the Trigger Event: Determine if the machine was recently stalled or bogged down under heavy load, which can cause the ECU to misinterpret sudden deceleration as signal noise.

2. 2

   Visual Inspection: Inspect the crankshaft position sensor and its wiring harness for physical damage from debris, sticks, or stumps.

3. 3

   Voltage Test: Turn the key to the ON position and use a multimeter to check for a 5V reference signal between position 1 on the sensor connector and the ground.

4. 4

   Resistance Test: Check the resistance between pins 2 and 3 on the Hall Effect sensor to ensure it does not read as zero (shorted) or infinite (open).

5. 5

   Check for Service Bulletins: For L3301 and L3901 models, check if the machine qualifies for Kubota Service Bulletin PSB-2015-051-R1, which addresses false P0336 codes via a software update.

1. 1

   Repair Wiring

   If the harness was torn by debris, repair the damaged wires or replace the pigtail connector, ensuring the pins are seated tightly and free of corrosion.

2. 2

   Replace the Sensor

   If the sensor is physically cracked or fails the resistance test, unbolt the old sensor, clean the mounting surface, and install the new crankshaft position sensor.

3. 3

   Clear the Code

   If the code was triggered by a stall and no physical damage exists, have a dealer hook up the Kubota Diag laptop software to manually clear it (cannot be cleared by a standard OBD2 scanner or battery disconnect).

4. 4

   Update ECU Software

   If the machine is an L-series or MX-series experiencing repeated P0336 codes from minor stalls, have the dealer apply the ECU software patch (PSB-2015-051-R1) to adjust the threshold for crank signal noise.