p0128
Moderate
Jaguar · Sedans & Sports Cars
Coolant Thermostat (Coolant Temperature Regulating System) Malfunction
Quick Answer
Error code P0128 on your Jaguar Sedans & Sports Cars means: Coolant Thermostat (Coolant Temperature Regulating System) Malfunction. This is usually fixable — see the step-by-step guide below.
Affected Models
Likely Causes
How to Fix It
1
Check coolant level
2
Monitor engine temperature gauge
3
Inspect coolant hoses
4
Test thermostat operation
5
Replace thermostat if stuck
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
Coolant
Hoses
Gasket
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