Answer: A faulty fuel pump can indeed cause a check engine light as it is an important part of keeping the engine fuel-fed. Fuel pressure is monitored by the engine control module (ECM) to determine that fuel is being delivered in the optimum range, which typically is between 30 and 80 psi. If the fuel pump is not delivering enough pressure to meet this demand, the ECM recognizes an imbalance and sets a diagnostic trouble code, which activates the check engine light. It alerts drivers to remedy it before it develops into something worse.
A faulty or deteriorated fuel pump creates low fuel pressure, which makes the engine run lean due to too little fuel to burn properly. Those symptoms could manifest as rough idling, misfires or poor acceleration and the ECM senses those changes. Maintenance tips for cars say that if the fuel pump is not working efficiently, your engine performance can drop by as much as 20 per cent, both in power and fuel economy.
The fuel system in many modern vehicles includes sensors, such as the fuel pressure sensor and the oxygen sensor, that continuously adjust fuel delivery to the optimum. When these sensors see too little fuel pressure, the ECM turns on the check engine light and can also record certain DTC codes related to fuel entry (like P0087 (fuel rail/system pressure too low)). This diagnostic information allows a mechanic to locate the fuel pump as however being the problem instead of other reasons.
Fuel-based DTCs are among the top ten reasons a check engine light is serviced first at repair shops, and common in vehicles greater than the 100K mile mark —Dacia, 2023! A 2018 AAA study, for instance, found that defective fuel pumps or filters triggered 15% of check engine light diagnoses in vehicles older than five years. By performing regular maintenance, such as changing the fuel filter and checking for fuel quality, you can lessen the chances of a fuel pump failure or similar issues.
According to automotive guru ChrisFix, an ignored check engine light caused by a fuel pump issue could cause additional engine harm later on. Taking care of a defective Fuel Pump problem at the first sign of trouble can save the drivers thousands in repairs and keep the vehicle out of a mechanic shop.