p0128
Moderate
Acura · SUVs
Coolant Thermostat (Coolant Temp Regulating Thermostat) Circuit/Performance Open
Quick Answer
Error code P0128 on your Acura SUVs means: Coolant Thermostat (Coolant Temp Regulating Thermostat) Circuit/Performance Open. This is usually fixable — see the step-by-step guide below.
Affected Models
Applies to all models
EL1YD3YD3-HYYD3-TSTB5TB5-ASYL1
Likely Causes
  1. Faulty thermostat stuck open
  2. Defective water pump
  3. Coolant leak
  4. Engine control module issue
  5. Sensor wiring problem
How to Fix It
1
Check coolant level and color
2
Monitor coolant temperature with diagnostic scanner
3
Feel upper radiator hose for proper temperature change
4
Perform thermostat replacement test
5
Replace thermostat if stuck open
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
Thermostat gasket
Related Error Codes
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