OBD codes / P0128 / Honda CR-V
P0128 on a Honda CR-V
Coolant Thermostat Below Regulating Temperature
K24 and 1.5T CR-V.
What P0128 usually means on a CR-V
P0128 means the CR-V is not reaching target temperature quickly enough, read by the ECU as a thermostat stuck open. It usually surfaces in cold weather as the thermostat wears, sometimes with a lukewarm heater. It is a routine, well-understood repair on this platform. Check coolant level and the temp sensor before replacing the thermostat.
Most likely causes on this model
- Thermostat stuck open
A worn thermostat that will not close is the dominant P0128 cause on CR-Vs.
- Faulty coolant temperature sensor
A low-reading sensor can trip the code with a good thermostat.
- Low coolant or air pocket
Insufficient coolant or trapped air skews warm-up.
What it costs on a CR-V
The thermostat is inexpensive with reasonable access on the CR-V, making this one of the cheaper temperature-related jobs. Confirm the temp sensor and coolant level first to avoid a redundant part. Installed cost typically lands in the low hundreds.
Year, engine and mileage change the answer. Get a diagnosis for your CR-V — it weighs these causes against your exact configuration and real complaint data.
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Related symptoms
Honda CR-V problems & recalls by year
Based on widely reported patterns for this model; individual causes vary by year, engine and history. Generic P0128 behavior is covered on the main P0128 page. Confirm with a scan tool before buying parts.