Electric Load Sensor: Description and Operation

Electrical Load Detector (ELD)

Since the early �90s, Honda vehicles have come with an electrical load detector (ELD) unit in the under-hood fuse/relay box. This unit allows the ECM/PCM to regulate the alternator (switch it between high output and low output) to provide the best combination of fuel economy and electrical system operation. The ELD sends a signal to the ECM/PCM that is proportional to the electrical demand. The ECM/PCM switches the alternator between high output and low output depending on several factors, which include electrical demand, battery charge level, and the driving cycle. When the alternator is in low output, the engine load is reduced and fuel economy improves.