L
p0128
Moderate
Land Rover · SUVs
Coolant Thermostat (Coolant Temp Regulation) Malfunction
Quick Answer
Error code P0128 on your Land Rover SUVs means: Coolant Thermostat (Coolant Temp Regulation) Malfunction. This is usually fixable — see the step-by-step guide below.
Affected Models
Applies to all models
D110D130D90L462L550L460L551L565L560
Likely Causes
  1. Stuck-open thermostat
  2. Faulty coolant temperature sensor
  3. Cooling system air pocket
  4. Water pump bearing wear
How to Fix It
1
Allow engine to warm up and monitor coolant temperature
2
Check if engine reaches normal operating temperature
3
Perform coolant system bleeding if air locked
4
Replace thermostat if stuck open
5
Verify temperature sensor readings
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 (appropriate type)
Gaskets and seals
Coolant temperature sensor (optional)
Related Error Codes
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