Case IH 19662 – Engine Control Module (ECM): Fuel pressure sensor voltage is higher than expected

This code indicates that the signal voltage sent from the high-pressure fuel rail sensor (or prefilter fuel pressure sensor) to the control module is above the normal operating range. This is typically caused by a wiring issue (such as a short circuit to a high voltage source or an open ground), a failed sensor, or an actual overpressure condition in the fuel rail.

• Tier 4b
• Puma series (140, 150, 165, 185, 200, 220)
• Maxxum
• Magnum
• Optum series
• 240 Series Axial-Flow Combines
• N-Series Loader Backhoes (TLBs)

1. 1

   Scan and Verify: Use the Case IH EST (Electronic Service Tool) or PT-Box to verify if the code is active. Check for related codes, such as 19666 (Quantity balance check / PRV forced open) or 3105 (Fuel pressure relief valve forced open).

2. 2

   Visual Inspection: Inspect the fuel pressure sensor, its electrical connector, and the wiring harness. Look for damaged wires, bent or dislocated pins, and corroded terminals.

3. 3

   Wiggle Test: Flex the wiring harness near the sensor while monitoring the sensor voltage on the diagnostic display to reveal intermittent breaks or shorts.

4. 4

   Circuit Testing: Using a multimeter, check the sensor connector for proper 5V reference voltage and a solid ground. Test the signal wire for continuity to the ECM and ensure it is not shorted to battery voltage (which would cause the 'higher than expected' voltage reading).

1. 1

   Power Down

   Turn off the engine, remove the key, and allow the engine to cool and the fuel system pressure to bleed off completely.

2. 2

   Repair Wiring (If Applicable)

   If the diagnostic checks revealed a short to power or an open ground in the harness, repair the damaged wire or splice in a new connector pigtail. If the wiring is sound, proceed to replace the sensor.

3. 3

   Clean the Area

   Thoroughly clean the fuel rail around the sensor to prevent any dirt or debris from contaminating the high-pressure fuel system.

4. 4

   Remove the Sensor

   Disconnect the electrical connector and carefully unscrew the faulty fuel pressure sensor from the fuel rail.

5. 5

   Install the New Sensor

   Thread the new OEM fuel pressure sensor into the rail. Torque it strictly to the manufacturer's specifications (over-tightening can damage the rail or sensor).

6. 6

   Reconnect

   Plug the electrical connector back into the sensor, ensuring the locking tab clicks into place.

7. 7

   Clear Codes and Test

   Turn the key to the ON position. Use your diagnostic tool to clear the 19662 fault code. Start the engine, check the fuel rail for any leaks, and verify that the fault code does not return. (Note: If the code clears but the engine still runs poorly, the Pressure Relief Valve (PRV) may have been tripped and might also require replacement).