Hi, 2016 Range Rover Sport Supercharged -85K miles- Out of Warranty. Code using an IIDTool BT P0089-64 (E8) Fuel Pressure Regulator Performance- Algorithm based failure-Signal Plausibility Failure. Search on the Internet mentioned. Might need to Update the PCM Software..How does one do that? A Part might be bad. Which Part is bad? Fuel Pump? Low Pressure or High Pressure Pump? Sensor or Sensors? Regulator?