P1026 on Lincoln
Engine Coolant Temperature Sensor 1 / Cylinder Head Temperature Sensor 2 Correlation
P1026 on Lincoln vehicles indicates engine coolant temperature sensor 1 / cylinder head temperature sensor 2 correlation. Au7o has documented this code across 1 Lincoln model — most commonly on Nautilus. 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. Typical repair costs on Lincoln range from $600 to $9,000, depending on the specific model and root cause.
Common Causes of P1026
- •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- •Outdated PCM calibration (TSB update required)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
P1026 on Lincoln by Model
Lincoln Nautilus(1 issue)
- 2.0L EcoBoost coolant loss / EGR cooler leak — low coolant, white smoke, overheat2019-2020
2019-2020 Nautilus models with the base 2.0L EcoBoost (non-hybrid) suffer unexplained coolant loss, white tailpipe smoke, an overheat warning, and sometimes coolant intrusion into the cylinders. Ford TSB 20-2234 traces the most common cause to a failing exhaust gas recirculation (EGR) cooler that leaks coolant internally; the related design also has a known coolant-intrusion weakness (narrow coolant slit between cylinders compromising the head-gasket seal). Owners report repeated coolant top-offs with no visible external leak, then misfires as coolant fouls the plugs. A June 2025 Ford EcoBoost coolant-intrusion class action covers 1.5L-2.0L engines; the most severe Nautilus cases require engine replacement with the redesigned block.
Looking for P1026 on a different make?
View P1026 across all makes →Frequently Asked Questions
What does P1026 mean on 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 specifically, this code is documented across 1 model.
What causes P1026 on Lincoln vehicles?▼
Common causes on Lincoln: 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). Specific causes vary by model and year — see the per-model sections below.
How much does it cost to fix P1026 on a Lincoln?▼
Repair costs on Lincoln range from $600 to $9,000, depending on the specific model and root cause.
Which Lincoln models have P1026 documented?▼
Au7o has documented P1026 on 1 Lincoln model: Nautilus.