Vehicle: 2021 Toyota RAV4, 4WD, L4-2.5L (A25A-FKS), Automatic Transmission/Transaxle

Mileage: 163,956

Problem: This vehicle came in with a customer concern of stalling when stopping or idling and sometimes while driving. Each time the engine restarted. The customer stated that several other shops had worked on the vehicle and replaced the mass air flow (MAF) sensor, purge valve and spark plugs, but the problem wasn’t fixed.

Case Details: The technician scanned all modules for diagnostic trouble codes (DTCs) and found none. He noticed that the RPM occasionally dropped to around 400 RPM. He performed a smoke test on the intake and found no leaks, then he tested the purge valve and MAF sensor. Everything was working well.

Next, he reset all adaptations and performed an idle relearn. The engine ran normally in the shop, but the issue returned during a test drive. The technician decided to take the diagnosis in a different direction. He checked the charging system and performed a battery load test. The battery failed the load test.

Confirmed Repair: The battery was replaced, the battery terminals and grounds were cleaned, all adaptations were reset again, and an idle relearn was performed. A good test drive confirmed that the problem had been resolved. Fixed!