P0128

Low urgency

Coolant Temperature Below Thermostat Regulating Temperature

What this code means

The engine takes too long to warm up - the ECU sees coolant temperature staying below where the thermostat should regulate it.

Common symptoms

Heater blows lukewarm air
Temperature gauge reads low
Slightly higher fuel consumption

Most common causes

Thermostat stuck open (most common)
Faulty coolant temperature sensor
Low coolant level

Can you keep driving?

Safe to drive, but a cold-running engine wears faster and burns more fuel - replace the thermostat at your next visit.

Do not guess in the dark

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Find a repair shop

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Descriptions are for guidance only. Accurate diagnosis requires a workshop inspection.