What Does P0168 Mean? OBD-II Code Powertrain Control Module (PCM) failure is defined as a Fuel Temperature Too High The Fuel Temperature Sensor tells the engine control module (PCM) the temperature of the fuel. When the PCM detects the Fuel Temperature is too high from the Fuel Temperature Sensor, the PCM will set code P0168. engine code P0168P0168 fixobd P0168dtc P0168obd code P0168obd2 P0168P0168 car codediagnostic code P0168car code P0168check engine code P0168fehlercode P0168P0168 fiatcodigo P0168codigo falla P0168P0168 kody b??dówcodigo de falla P0168 What are the common causes of P0168 ? Potential causes for this code to set are: Defective fuel composition/temperature sensor A bad ambient temperature sensor Faulty intake air temperature sensor Open, shorted, or damaged wiring or connectors PCM or a PCM programing error What are the symptoms of P0168 ? A stored code P0168 should be treated as severe because fuel temperature is used by the PCM to calculate fuel delivery strategy in flex fuel vehicles. Symptoms of this code may include: Usually no symptoms accompany a code P0168 Other fuel composition codes may be present MIL illumination will eventually occur How do you troubleshoot P0168 ? Step 1 Record all fault codes present, as well as all available freeze frame data. This information can be of use should an intermittent fault be diagnosed later on. NOTE: Take careful note of other codes that may be present along with P0168, and particularly codes that indicate short circuits or high resistances in the fuel system. Refer to the manual for detailed information on the possible relationship between additional codes and P0168, and repair these codes first if the manual recommends it, since these types of codes are often the direct cause of P0168. Step 2 Since poor fuel quality is often implicated in the setting of this code, consider the possibility that the fuel in the vehicle might be the cause of the problem. Thus, if the code appeared soon after adding fuel, consider replacing that fuel, or adding high quality branded fuel in an effort to resolve the code. At this point, it might be a good idea to take a reading of the fuel’s actual temperature if an oscilloscope and reference data is not available. Compare this reading with the value stated in the manual, since there is no single fuel temperature that is valid for all applications under all conditions. Most manufacturers specify exact temperatures the fuel must be at under a variety of conditions, so make sure to obtain as many temperature readings as the manual demands in order to obtain the most accurate test results. If the actual fuel temperature is available, it becomes easier to determine whether a reading from the fuel composition/temperature sensor is plausible or not. However, making this determination with the aid of an oscilloscope is much easier, since all guesswork is removed from the equation, so to speak. Step 3 If the code persists, but the fuel in the vehicle is known to be good, and there are no additional codes present (including pending codes), refer to the manual to locate and identify all relevant components and wiring. Also, use this opportunity to determine the location, routing, function, and color-coding for all associated wiring. Perform a thorough visual inspection of all associated wiring, and look for damaged, burnt, shorted, disconnected, or corroded wiring and connectors. Make repairs as required, clear all codes, and operate the vehicle for at least one complete drive cycle to see if the code returns. Step 4 If the code persists but the wiring is free of visible damage, prepare to perform reference voltage, ground, resistance, and continuity checks on all associated wiring. However, be sure to disconnect all wiring from the PCM and other affected controllers during resistance and continuity checks to prevent damage to one or more controllers. Pay particular attention to the 5-volt reference and ground circuits. In most cases, the ground is supplied by the PCM, so if obtained readings do not conform to specified values, test the relevant pins on the PCM for ground and a 5-volt current in the reference voltage circuit. Replace the PCM if it delivers neither the ground, nor the reference voltage. Keep in mind though that PCM failure is rare, and the fault is therefore much more likely to be the result of some other failure, such a failure of the fuel composition / temperature sensor itself. Bear in mind also that the sensor forms part of the circuit, and as such, its internal resistance and continuity must be tested as well. Consult the manual on the correct procedure to follow to test the sensor, and replace the sensor if any obtained reading does not fall within the specified range or value. Also, note that continuity and resistance values must match specified values exactly, or very nearly so, but in all cases, obtained readings MUST fall within the ranges specified by the manufacturer. If discrepancies are found, make repairs or replace wiring as required to ensure that all electrical values fall within the manufacturer’s specifications. Clear all codes after repairs are complete, and operate the vehicle for at least one complete drive cycle to see if the code returns. WARNING: Take note that extreme care MUST be taken when testing currents at any pin on any PCM, since accidental contact with the wrong pin or terminal can cause severe damage to the PCM. Perform these tests in strict accordance with the instructions in the manual, or refer the vehicle for professional diagnosis and repair if you are not comfortable with the idea of testing circuits directly on the PCM. Step 5 Although Steps 1 through 4 will resolve code P0168 in a large percentage of cases, some stubborn cases may not be resolvable without using an oscilloscope to properly analyze the signal generated by the fuel composition/temperature sensor. Thus, if an oscilloscope is not available, resist the temptation to throw parts at the problem in the hope of hitting the solution by accident. In these cases, the wisest course of action is always to refer the vehicle to the dealer or other competent repair shop for professional diagnosis and repair. Searches related to P0168 - Fuel Temperature Too High p0169 p0168 jeep p0168 code fuel temperature sensor location p0178 p1682 p0138 p0128
