P0501 is an OBD2 trouble code that indicates there is an issue with your Mercury Grand Marquis’s Vehicle Speed Sensor (VSS). It occurs when the Powertrain Control Module (PCM) gets a signal from the VSS outside its normal operating range (in terms of voltage). P0501 is a generic powertrain code, which means it has the … Read more
P0008 is a somewhat uncommon OBD2 trouble code that can occur in the Mercury Grand Marquis. It indicates that the crankshaft and camshaft are not synchronized properly, and should be considered a breakdown risk. Driving your Grand Marquis with P0008 can lead to engine damage and a costly repair. While P0008 is a generic code … Read more
P144C is a Ford-only DTC trouble code, and as such, it applies to your Mercury Grand Marquis. It indicates that the EVAP canister purge check valve is not performing within spec. P144C is most often fixed by replacing the EVAP purge valve assembly (due to the purge valve being stuck open or closed), which can … Read more
P0725 is a common OBD2 code that can occur in the Mercury Grand Marquis. It indicates an issue with the engine speed sensor input circuit (which measures the engine speed at the input shaft and helps the PCM determine when and how hard to shift the transmission). It’s a generic code, which means it has … Read more
P0193 is a generic OBD-II code that can occur in the Mercury Grand Marquis. It indicates that your Grand Marquis’s fuel rail pressure sensor is sending a signal to the PCM that is above its normal operating range (in terms of voltage value). While P0193 is a generic code (it has the same meaning for … Read more
P0523 is a standard OBD2 trouble code that can occur in the Mercury Grand Marquis. In layman’s terms, it indicates the signal from the oil pressure sensor is higher than its normal operating range (in terms of voltage). P0523 is generic (it has the same definition for all vehicles), repair steps will depend on your … Read more
P0705 is a very common transmission-related trouble code that can occur in the Mercury Grand Marquis. In layman’s terms, it means that your Grand Marquis can’t tell what gear you’ve selected, which can have some real consequences on how it drives. It’s most likely caused by a bad Transmission Range Sensor (TRS), but there are … Read more
P1450 is a manufacturer-specific trouble code. In the case of Ford-made vehicles (such as the Mercury Grand Marquis), it indicates that the pressure in the fuel tank is not bleeding up to the engine. This code is very common, and not a breakdown risk when it appears by itself. Far and away, the most common … Read more
P1289 is a manufacturer-specific diagnostic trouble code. In the case of Ford-built vehicles (such as the Mercury Grand Marquis), it indicates that the cylinder head temperature sensor returned a value to the powertrain control module (PCM) that was greater than the signal should be during a self-test cycle. The most likely cause of P1289 is … Read more
P2271 is a generic DTC trouble code that can affect the Mercury Grand Marquis. It indicates that the oxygen sensor located on bank 1 in the second position is continuously sending voltage with a value that is too rich. There are oxygen sensors on both sides of the catalytic converter. The “upstream” one is used … Read more