Question 1

What does P0125 mean?

Accepted Answer

P0125 - Insufficient Coolant Temperature for Closed Loop. Engine not reaching high enough temperature for closed-loop fuel control.

Question 2

What are the symptoms of P0125?

Accepted Answer

Check engine light, Slow warm-up, Poor heater, Poor fuel economy

Question 3

What causes P0125?

Accepted Answer

Thermostat stuck open, Missing thermostat, Incorrect thermostat rating, ECT sensor reading low

Question 4

How much does it cost to fix P0125?

Accepted Answer

Typical repair cost: $15-$200. Replace the thermostat. $15-50 fix.

P0125 — Insufficient Coolant Temperature for Closed Loop

Don't guess — diagnose P0125 the right way