p0128
Moderate
Suzuki · SUVs & Crossovers
Coolant Thermostat (Coolant Temp Regulation) Malfunction
Quick Answer
Error code P0128 on your Suzuki SUVs & Crossovers means: Coolant Thermostat (Coolant Temp Regulation) Malfunction. This is usually fixable — see the step-by-step guide below.
Affected Models
Likely Causes
How to Fix It
1
Monitor engine coolant temperature during warm-up cycle
2
Test coolant temperature sensor resistance values
3
Check coolant level and condition
4
Perform cooling system pressure test
5
Inspect water pump flow and bearing condition
Pro Tip
This fix requires some technical knowledge. If you're unsure about any step, consider contacting support or a qualified technician.
Parts You May Need
Thermostat assembly
Coolant temperature sensor
Coolant (appropriate type)
Water pump
Pressure test kit
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