P1026 on Lincoln: How to Diagnose & Fix
Engine Coolant Temperature Sensor 1 / Cylinder Head Temperature Sensor 2 Correlation
1 Lincoln model · 1 documented issue · 1 critical
P1026 on Lincoln by model: symptoms, diagnosis and fix
Some 2.0L EcoBoost Nautilus SUVs may show low coolant, white smoke from the tailpipe, an over-temperature warning, an external coolant leak and/or a check-engine light with stored codes. Ford attributes this to the exhaust gas recirculation (EGR) cooler and/or PCM software settings. It affects 2019–2020 Lincoln Nautilus with the 2.0L EcoBoost engine; bulletin 20-2234 also covers the 2019–2020 Ford Edge 2.0L.
Common Symptoms
- Low coolant level
- White smoke from the tailpipe
- Over-temperature warning
- External coolant leak
- Check-engine light
How to Fix
Have a dealer confirm the symptoms and codes. Bulletin 20-2234 has vehicles built on or before 9-Jul-2020 get the latest PCM software first, then a cooling-system pressure test and inspection of the EGR cooler for damage or internal leaks; if the EGR cooler leaks, the EGR cooler and EGR outlet tube are replaced. If the cooler does not leak, the technician follows standard workshop-manual diagnosis. Normal warranty rules apply; this is not a recall or a promise of free repair.
Sources for this issue (2)
P1026 code reference
General diagnostic-code context. The code alone does not confirm a cause for your vehicle; use the applicable issue card and its sources.
Frequently asked questions
What does P1026 mean on a Lincoln?
P1026 stands for "Engine Coolant Temperature Sensor 1 / Cylinder Head Temperature Sensor 2 Correlation." The PCM cross-checks the engine coolant temperature (ECT) sensor against the cylinder head temperature (CHT) sensor. P1026 sets when the two readings disagree by more than a calibrated amount, meaning one sensor is reading incorrectly or coolant is not actually present at the ECT sensor while the head is heating. Ford TSB 20-2234 lists P1026 among the codes (with P0128, P0217, P044C, P1285, P1299, P139A, P2457) stored on 2019-2020 Edge / Lincoln Nautilus 2.0L EcoBoost vehicles suffering coolant loss from a cracked EGR cooler; because the PCM uses this correlation to protect the engine, it will often move into a fail-safe cooling / reduced-power strategy. On Lincoln it is documented across 1 model: Nautilus.
What are the most common causes of P1026?
The most common causes of P1026 are: Coolant loss — notably a cracked or leaking EGR cooler on 2.0L EcoBoost (Ford TSB 20-2234), Low coolant level or air trapped in the cooling system so the ECT sensor is not immersed, Failed or drifting ECT or CHT sensor, Damaged ECT / knock-sensor wiring harness (a known 2.7L EcoBoost concern), Outdated PCM calibration (TSB update required), Stuck thermostat or other cooling-system fault causing genuine temperature divergence. The specific cause varies by vehicle.
How much does it cost to fix P1026 on a Lincoln?
Repair costs vary widely with the root cause and Lincoln model; each issue on this page carries its own estimate where one is published.
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Content compiled with AI assistance using NHTSA complaints, TSBs, and owner reports. May contain errors. Always verify with your vehicle's service manual.