Lexus ES 350 electrical warnings, communication faults, and wiring diagnosis This Lexus ES guide is based on 3 documented technical cases, including 2 confirmed successful repair outcomes. It summarizes the captured evidence without assuming every vehicle with a similar symptom has the same cause. Documented applicability includes 2013.
What Drivers or Technicians Reported
Documented complaints included: Both cooling/A/C fans did not run automatically.; No crank and no PCM communication remained after another shop replaced the PCM.; Battery died after more than eight hours parked..
Causes Confirmed in Documented Cases
Failed EFI Main Relay. Aftermarket alarm causing key-off current draw.
What the Diagnostic Process Found
Sizeable draw present Draw disappeared with 15A TV fuse removed
Repairs That Corrected Documented Cases
Replace EFI Main Relay Remove aftermarket alarm
Repairs or Attempts That Did Not Solve the Original Problem
Replace ECT sensor — no change Replace cooling fan module — no change Replace PCM — unsuccessful
Lexus ES Diagnosis in Hickory, NC
Mich's Foreign Cars has served Hickory and the surrounding Western North Carolina area since 1983. We specialize in European and foreign vehicles and use professional diagnostic equipment to identify the cause before recommending repairs. If your Lexus ES is showing this symptom or fault pattern, call Mich's Foreign Cars at 828-324-6012 to schedule diagnosis.