Case IH 19535 – Engine Control Module (ECM): ECM Internal: Too high injector energizing time during Over Run

The Engine Control Module (ECM) has reached its maximum correction limit for a fuel injector's energizing time during the Zero Fuel Mass Calibration (ZFC) learning process. This occurs in an 'over run' condition and indicates the injector is worn, clogged, or suffering from a hydraulic pressure drop.

• Tier 4b
• Puma 115
• Puma 125
• Puma 140
• Puma 150
• Puma 155
• Puma 165
• Puma 185
• Puma 200
• Maxxum 115
• Maxxum 125
• Maxxum 140
• Maxxum 150
• Magnum 180
• Magnum 200
• Farmall 110A
• Farmall 120A
• Farmall 130A
• Farmall 140A
• Farmall 115U Pro EP
• Vestrum 100
• Vestrum 110
• Vestrum 120
• Vestrum 130

1. 1

   Scan the ECM for other fuel pressure codes (e.g., rail pressure too low) or circuit codes (e.g., short to ground/battery on the injector harness) that could artificially cause the energizing time to increase.

2. 2

   Verify the low-pressure fuel supply and replace the primary and secondary fuel filters to rule out fuel starvation or aeration.

3. 3

   Perform a return flow (leak-off) test on the injectors to see if a specific injector has excessive internal leakage causing a pressure drop.

4. 4

   Use the dealer diagnostic tool (e.g., CNH EST) to run an injector balance test (cylinder contribution test) to isolate the specific worn injector.

1. 1

   Identify the Faulty Injector

   Use your diagnostic scan tool to read the sub-codes or cylinder-specific codes to identify which injector has reached its maximum energizing time limit.

2. 2

   Depressurize and Clean

   Relieve the high-pressure fuel system. Thoroughly clean the area around the affected fuel injector to prevent debris from entering the cylinder head or fuel rail.

3. 3

   Remove the Injector

   Disconnect the electrical connector and the high-pressure fuel line from the injector. Remove the injector hold-down clamp and extract the injector.

4. 4

   Install the New Injector

   Install the replacement fuel injector using a new sealing washer and O-ring. Reinstall the hold-down clamp and torque to the OEM specification.

5. 5

   Reconnect

   Reattach the high-pressure fuel line and plug in the electrical connector.

6. 6

   Program the Injector (IQA/IMA)

   Using the diagnostic scan tool, enter the new injector's trim code (calibration code) into the ECM. This is critical, as the ECM needs the new baseline to calculate the correct energizing time.

7. 7

   Test Drive

   Clear the fault codes and test drive the tractor. Ensure you allow the machine to enter an 'over run' state (coasting/decelerating with zero throttle) so the ECM can run the Zero Fuel Calibration monitor and verify the repair.