Case IH 19716 – Engine Control Module (ECM): Leakage is detected based on fuel quantity balance (tank low condition)

The engine's control system has detected a discrepancy between the commanded fuel quantity and the actual fuel rail pressure response. The system calculates the fuel quantity balance via the fuel metering unit and the rail pressure sensor. If the rail pressure drops below the expected threshold, the system suspects a high-pressure fuel leak. The 'tank low condition' modifier indicates this was flagged while the fuel level was low, which can cause the fuel pump to draw air into the low-pressure fuel system, causing pressure fluctuations that mimic a leak.

• Tier 4b
• Case IH Farmall and Maxxum series tractors
• Case IH Axial-Flow Combines (7230, 8230, 9230, 7250)
• Case Construction equipment (N-Series Backhoe Loaders, Skid Steers, Wheel Loaders)

1. 1

   Check the physical fuel level (do not rely solely on the gauge if a faulty sender is suspected).

2. 2

   Inspect the low-pressure fuel lines, water separator, and filter housings for loose fittings or cracked lines where air could be drawn into the system.

3. 3

   Visually inspect the high-pressure fuel pump, high-pressure lines, fuel rail, and injector connections for raw diesel leaks.

4. 4

   Check the Fuel Pressure Relief Valve (PLV) on the fuel rail to see if it is stuck open or leaking internally, dumping high-pressure fuel back into the return line.

5. 5

   Check fuel filters for severe restriction, which can starve the high-pressure pump and cause a pressure drop that mimics a leak.

1. 1

   Refuel and Bleed

   If the tank is low or empty, fill the fuel tank with clean diesel. Prime and bleed the low-pressure fuel system to purge any trapped air.

2. 2

   Replace Fuel Filters

   If the filters are due for service or show signs of restriction/water contamination, replace both the primary (water separator) and secondary fuel filters.

3. 3

   Address External Leaks

   If a physical leak is found on a high-pressure line, replace the affected line. Note: High-pressure common rail lines are single-use and must be replaced once loosened.

4. 4

   Test/Replace the Pressure Relief Valve

   If no external leaks or air intrusion are found, run the engine and monitor the fuel return line from the fuel rail pressure relief valve. If fuel is passing through the valve under normal operating pressures, the valve (or the entire rail, depending on the engine model) must be replaced.

5. 5

   Clear and Verify

   Use the CNH Electronic Service Tool (EST) to clear the fault code. Test run the machine under a heavy load to verify that the actual rail pressure matches the commanded setpoint and the code does not return.