Flex Fuel Sensor - AC Delco

rdperformancefab Verified independent store

→

This inline fuel sensor is designed to measure the ethanol to gasoline ratio in real time. By sending a frequency based signal to the ECU it allows the engine management system to automatically adjust fueling and ignition for blends ranging from pure gasoline to E85. Physical Specs Part Number: 13577379 Weight: ~0.28 lb. (≈128 g) Size: 4.4 in long × 3.5 in wide × 1.6 in tall Housing/Ports: Fuel flows through the sensor body which uses quick connect style fittings (commonly 3/8 in) Connector: 3 pin oval female style with blade type terminals Electrical and Signal Wiring: Three connections: 12V supply ground and signal output Output Type: Digital square wave frequency proportional to ethanol concentration Typical Range: ~50 Hz (gasoline) up to ~150 Hz (E85) Fault Indication: Frequencies in the 180 to 190 Hz range can signal contamination or a sensor issue Signal Handling: Most ECUs provide a 5V pull up with the sensor pulling the signal to ground in pulses Functionality All of the vehicle's fuel passes through the sensor before reaching the injectors, so the composition reading reflects actual fuel mix The internal processor not only reports ethanol percentage but also monitors for abnormal fuel conditions Data from the sensor enables adaptive engine control strategies like timing and fueling adjustments for safe and efficient operation across different fuel blends Show more