Lexus RX · Diagnostic Trouble Code
P0128 — Coolant Thermostat (Coolant Temp Below Regulating Temp)
Quick overview of P0128 on your Lexus RX. Read the full diagnosis guide, then find the repair guides for your vehicle below.
Repair guides that fix P0128
General diagnostic information, not a factory service procedure. If you're unsure, have a qualified technician confirm the diagnosis before buying parts.