Case IH 19590 – VCM (Vehicle Control Module) or Engine ECU: Maximum Signal Error

This fault code indicates that a sensor is returning a voltage or signal value that exceeds the maximum allowable threshold (typically indicating a short-to-power or an open circuit). It is specifically tied to the Oil Level Sensor.

• Tier 4b
• Magnum
• Steiger
• Maxxum
• Farmall
• 6130
• 7120
• Axial-Flow
• N-Series Loader Backhoes
• 580N

1. 1

   Stop the machine on level ground and manually check the engine oil (or hydraulic oil) level using the dipstick/sight glass to ensure the system is not drastically overfilled.

2. 2

   Inspect the wiring harness leading to the oil level sensor on the oil pan/sump. Look for rubbed wires, corrosion inside the connector, or a short-to-battery voltage.

3. 3

   Check for accompanying active codes such as 19593 (Oil level sensor fault) or 19589 (Oil dilution) which will confirm the sensor has failed entirely.

1. 1

   Prep the Machine

   Park the machine on a level surface, turn off the engine, and allow the oil to cool.

2. 2

   Drain the Fluid

   Place a clean catch pan beneath the oil sump/pan and drain the oil below the level of the sensor (or drain completely if an oil change is due).

3. 3

   Remove the Sensor

   Disconnect the electrical harness from the oil level sensor. Unthread the sensor from the oil pan.

4. 4

   Install the New Sensor

   Thread the new sensor into the port. If it is an M12 threaded sensor (common on F4HFE Tier 4 engines), torque it to 10 - 14 Nm (7.4 - 10.3 lb ft).

5. 5

   Reassembly

   Reconnect the electrical harness. Refill the engine (or hydraulic reservoir) with the manufacturer-approved fluid to the correct level.

6. 6

   Clear Codes

   Turn the key on, clear the stored fault codes via the AFS Pro display or diagnostic tool, and start the engine to verify the code does not return and there are no leaks.