Vehicle: 2011 Ford Crown Victoria, V8-4.6L Flex Fuel

Mileage: 141,009

Problem: The vehicle was brought to the shop because the engine would intermittently stall during various driving conditions and the malfunction indicator light (MIL) was on.

Details: The technician connected a scan tool and retrieved diagnostic trouble code (DTC) P018C – Fuel Pressure Sensor B Circuit Low. He connected a fuel pressure gauge to monitor the pressure. It was within specifications. At this point, he called ALLDATA Tech-Assist.

The Tech-Assist consultant suggested monitoring the fuel rail pressure sensor parameter Identification Data (PID) and compare that to the actual pressure on the mechanical gauge to ensure the correct fuel pressure values were being sent to the powertrain control module (PCM).

The results of that test revealed that the fuel rail pressure (FRP) sensor did not respond to changes in fuel pressure under different conditions when compared to the mechanical fuel pressure gauge readings.

Confirmed Repair: The technician replaced the FRP sensor and retested the fuel pressure. This time the fuel rail pressure sensor PID on the scan tool matched the mechanical gauge fuel pressure readings. He cleared the DTC and test drove the vehicle. The engine did not stall, and the MIL stayed off. Problem solved!