C3977 Mercedes-Benz Auto Trouble Code

C3977 Mercedes-Benz OBD2 reports a sensor fault, replacement of the sensor is unlikely to resolve the underlying problem. The fault is most likely to be caused by the systems that the sensor is monitoring, but might even be caused by the wiring to the sensor itself.

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.

C3977 Mercedes-Benz Possible Solution:

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.

C3977 Mercedes-Benz Description For All Models :

C3977 Mercedes-Benz Trouble Repair :

With C3977 Mercedes-Benz code so start with the basics like a fuel pressure and fuel volume test. Or, you can start on the electrical side by doing a voltage drop on both the power and ground connections for the fuel pump. Some shops are reporting corrosion on the fuel pump ground that reduces power and fuel pressure.

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