This diagnostic trouble code (DTC) is a generic OBD-II powertrain code. It is considered generic because it applies to all makes and models of vehicles (1996-newer), although specific repair steps may vary depending on the make and model.

A good starting point is always to check for technical service bulletins (TSB) for your particular vehicle. Your issue may be a known issue with a known fix put out by the manufacturer and can save you time and money during diagnosis.

Most turbocharger boost controllers are programmed to effect between nine and fourteen-pounds of boost pressure. The boost pressure bypass control valve is opened and closed (via an electrical signal from the PCM) as much as is required to maintain an acceptable degree of turbocharger boost pressure.

When attempting a diagnosis for this code, I begin with a thorough inspection of all wiring and vacuum hoses related to the turbocharger and boost control system.

I would proceed by reading and recording all trouble codes, then clearing the codes from the system. This serves two purposes; if the code fails to reset, you know that it is intermittent and, if your vehicle places the boost pressure bypass valve in the wide-open position when this type of code is stored, it will allow the system to return to a normal operating mode prior to further testing.

Accelerator Pedal Position Sensor 1 Circuit Low and P2127 - Accelerator Pedal Position Sensor 2 Circuit Low would lead you to suspect a defective accelerator pedal position sensor.

In-line Ford engines, along with those of most other manufacturers, begin the numbering of cylinders at the front and proceed in numerical order toward the back. In the V-engine design, Ford follows a similar design with the number one cylinder at the front left of the engine. In the V-6 configuration, cylinder 4 is at the front right of the engine and in a V-8, cylinder number 5 is in that location. Other manufacturers sometimes use an alternating pattern in the V-engines.