Intermittent Fuel Pump shutdown can be caused by voltage fluctuations, filter clogging or erratic ECU signals. Let’s use the Volkswagen MQB platform as an example. When the contact resistance of its fuel pump relay (J17) rises from the normal 0.05Ω to 0.5Ω, it will cause the supply voltage to drop from 12.8V to 9.3V (below the lower limit of 9.5V in the ISO 16750-2 standard). Trigger the thermal protection shutdown of the pump body (armature temperature ≥ 120℃). As per the 2023 J.D. Power report, such voltage problems account for 23% of fuel pump failures, and the repair will cost approximately $150- $400 (inclusive of wiring harness replacement).
A clogged fuel filter (pressure difference ≥ 15 psi) will cause the pump body to operate beyond its capacity. For example, when the filter of the original factory pump (flow rate 180 L/h) of the Ford Ecoboost 1.5T engine is blocked, the flow rate drops to 110 L/h (down by 39%), and the armature current rises from 5A to 8A. The wear rate of the carbon brushes increases by 300% (the life is shortened from 1500 hours to 500 hours). 280,000 vehicles were recalled by Toyota in 2022 due to filter design issues. The pump body was closing down twice a week, as reported by users. The failure rate decreased by 89% after replacing the filter (NHTSA statistics).
The other main cause is sensor failure or ECU signal interference. When the fuel pump control module (FPCM) of the BMW B48 engine is disturbed by CAN bus noise (amplitude ≥ 2V, frequency 10-200 MHz), it will lead to the duty cycle command error ≥ ±15%, and fuel pressure deviation out of range (> ±8 psi), which will make the ECU shut down forcefully. In 2024, Automotive News reported that the incidence of these problems in the Mercedes-Benz M274 engine was 7%, and the fix included software updates and replacement of shielded wiring harness (with a budget of $600- $900).
Especially alarming is the unintentional engagement of the security mechanism. General Motors’ Fuel Pump inertial switch may be falsely deactivated when the vehicle bumps (acceleration ≥ 5G). For example, when the Chevrolet Silverado runs at 40 km/h on a gravel road, the downtime probability is 12% (SAE test data). The switch can be reset in just 10 seconds. But if it is activated more than 3 times a month, then the car body acceleration sensor needs to be checked (for 200 US dollars). Tesla Cybertruck’s intelligent pump eliminates invalid vibration signals through AI (false trigger rate from 8% to 0.1%), but it relies on OTA updates (for $150 each time).
Deterioration of fuel quality (e.g., water content ≥ 500 ppm) will cause corrosion of the pump body and trigger the thermal protection. A 2023 survey of Brazil’s National Petroleum Agency (ANP) discovered that vehicles powered with low-octane ethanol gasoline (E25 with moisture content higher than the spec) have four times as much fuel pump downtime as those powered with compliant fuel, and the life of the pump body is cut by 60% (from 1,200 hours to 480 hours). Regular usage of fuel cleaners (such as Red Line SI-1, $10 per bottle) can suppress the moisture content below 100 ppm and reduce the potential downtime by 75% (as Consumer Reports tested).