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OBDII Code List

P0128 CHEVROLET - Engine Coolant Temperature Below Thermostat Regulating Temperature

Repair Importance Level: 3/3
Repair Difficulty Level: 2/3 What does this mean?

Possible causes

  • Leaking or stuck open thermostat
  • Low engine coolant level
  • Insufficient warm up time
  • Faulty engine coolant temperature sensor
  • Engine coolant temperature sensor harness is open or shorted
  • Engine coolant temperature sensor circuit poor electrical connection
What does this mean?

Tech notes

If cooling system is not leaking and the fluid level is OK, replacing the thermostat usually takes care of the problem.
What does this mean?
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Posted and Edit by 06-14-2015