Not only that trouble code P0177 errors of the engine or other electronic systems of the car do not always indicate directly to the faulty element, but also in different makes and models of cars the same error can occur as a consequence of the failure of absolutely different elements of the electronic system.
We hope with your help to form the cause-and-effect relationship of this or that OBD2 error in a particular car (make and model). As experience has shown if we consider a certain make-model car, in the vast majority of cases the cause of the error is one and the same.
If the error indicates the wrong parameters (high or low values) of any of the sensors or analyzers, most likely this element is normal, and the problem should be sought “upstream”, in the elements whose work is analyzed by the sensor or probe.
If the error indicates a permanently open or closed valve, you need to approach the solution of the problem wisely and not mindlessly change this element. There can be several reasons: the valve is clogged, the valve is jammed, and the wrong signal comes to the valve from other malfunctioning nodes.
Errors of the engine OBD2 and other systems of the car do not always point directly to the malfunctioning element. The error itself is indirect data about the fault in the system, in a sense a clue, and only in rare cases a direct indication of a faulty element, sensor, or part.
Errors (error codes) received from the device, scanner requires the correct interpretation of the information, so as not to waste time and money on replacing working elements of the car.
The problem is often much deeper than it seems at first sight. This is caused by the fact that the information messages contain, as mentioned above, indirect information about the malfunction of the system.
Here are a couple of common examples. If the error indicates incorrect parameters (high or low values) of any of the sensors or analyzers, most likely this element is normal, as it analyzes (gives out some parameters or values), while the problem should be sought “upstream”, so to speak, in the elements whose work is analyzed by the sensor or probe.
If the error indicates a permanently open or closed valve, then you need to approach the solution of the problem wisely and not mindlessly change this element.
There can be several reasons: the valve is clogged, the valve is jammed, and the wrong signal comes to the valve from other defective nodes.
Another point that I would like to note is the specificity of this or that make and model. Therefore, having found out an error of work of the engine or other system of your car do not hasten to make hasty decisions, and approach to a question comprehensively.
The PCM has detected an incorrect voltage reading from the fuel composition sensor (flexible fuel sensor) or circuit. This sensor is designed to detect fuel (ethanol) contamination and provide accurate fuel temperature in the PCM.
Code Set Parameters
If the PCM detects an input from the fuel composition sensor that indicates the presence of non-gasoline (or non-ethanol in flex fuel vehicles) in excess of ten percent (check specifications for your specific vehicle), the code will be stored and the service engine light may soon illuminate. Some vehicles require several failure cycles for the service engine light to illuminate.
These can range from zero to serious engine skipping, hesitation, slack or stumbling when accelerating, or no starting conditions. Other fuel system codes may also be stored in addition to this code.
Fuel contamination is the most common cause of this code setting condition. Other causes may be a faulty fuel flow sensor, open, shorted or damaged wiring or connectors, or a faulty PCM.
Technicians report that the fuel composition sensor is often replaced by mistake when fuel contamination is the cause of the malfunction.