Back to 2018 Lincoln MKX

2018 LINCOLN MKX

2.7L EcoBoost V6•AWD•AUTOMATIC•gas•turbo
5 active safety recalls on this vehicle — view recalls
Repairs0Labor1190Torque9534Fluid15DTC1932Battery0Maintenance0Recalls5
P0125moderate severityPowertrain

Insufficient Coolant Temperature for Closed Loop Fuel Control

on 2018 Lincoln MKX 2.7L EcoBoost V6 · AWD

What this code means

The engine is not reaching normal operating temperature quickly enough for the PCM to enter closed-loop fuel control.

Symptoms

  • Check Engine Light
  • Poor fuel economy
  • Extended warmup time
  • Rich exhaust smell

Common causes

  • Stuck-open thermostat
  • Faulty ECT sensor
  • Cooling fan running constantly
  • Low coolant level

Diagnostic steps

  1. Monitor ECT warmup time (should reach 160°F within 5-10 min)
  2. Test thermostat
  3. Check cooling fan operation
  4. Test ECT sensor

Repair notes

Replace thermostat. Most common cause.

Other Powertrain codes on this vehicle

Building an app?
Free API access to all this data — 50 requests/day, no card required.
Get an API key →
Run a shop?
Manage repairs, estimates, and customers with ShopBase — $249/mo, all features included.
Try ShopBase →