Case IH 19441 – Engine Control Module (ECM / ECU): Over temperature on the PWM output power stage for the Engine Speed

The Engine Control Module (ECM) uses an internal driver circuit (a "power stage") to send a Pulse Width Modulated (PWM) engine speed signal to other modules, such as the instrument cluster or tachometer. This fault code indicates that this specific internal driver circuit is overheating. This is typically caused by excessive current draw on the circuit, usually due to a partial short-to-ground in the wiring harness or a failing receiving component that is pulling more amperage than the ECU's driver can handle.

• Tier 4b
• Magnum
• Steiger
• Puma
• Axial-Flow
• N Series Loader Backhoes

1. 1

   Visually inspect the wiring harness between the Engine ECU and the instrument cluster for chafing, pinched wires, or melted insulation that could cause a partial short to ground.

2. 2

   Disconnect the harness at the Engine ECU and the receiving module, and use a multimeter to check the engine speed signal wire for continuity, short to ground, or short to battery voltage.

3. 3

   Check the resistance of the receiving module's input pin to determine if an internal fault is causing it to draw too much current.

1. 1

   Power Down

   Turn off the machine, remove the key, and disconnect the negative battery terminal to prevent electrical spikes.

2. 2

   Isolate the Circuit

   Disconnect the main engine harness from the Engine ECU and the instrument cluster/cab bulkhead.

3. 3

   Repair Wiring (If Applicable)

   If the multimeter tests reveal a short to ground or high resistance in the engine speed signal wire, locate the damaged section of the harness. Splice and solder a new section of wire, sealing it with heat-shrink tubing, or replace the affected harness section.

4. 4

   Test with a Known Good Component

   If the wiring tests perfectly, the excessive current draw may be coming from the instrument cluster. If possible, temporarily connect a known-good cluster to see if the excessive draw disappears.

5. 5

   Replace the Engine ECU (If Necessary)

   If the wiring is intact and the receiving module is functioning correctly, the internal PWM power stage inside the Engine ECU is likely permanently damaged (burnt out) from a previous short. The ECU will need to be replaced and flashed with the correct software for the machine.

6. 6

   Clear Codes

   Reconnect all components, restore battery power, and use the CNH Electronic Service Tool (EST) to clear the inactive 19441 fault code. Run the engine to verify the tachometer works and the code does not return.