P0731 on Lincoln: How to Diagnose & Fix
Gear 1 Incorrect Ratio
2 Lincoln models · 2 documented issues · 1 critical
P0731 on Lincoln by model: symptoms, diagnosis and fix
Some 2020-2023 Lincoln Aviators equipped with a 10R60 and built on or before December 23, 2022, or a 10R80 MHT and built on or before August 15, 2022, may have harsh or delayed engagement and/or harsh or delayed shifts. Ford TSB 22-2428 says the condition may involve PCM/TCM software, the transmission solenoid-ID strategy, sticking main-control valves, or axial movement of the CDF clutch-cylinder sleeve. The complaint may occur with or without a malfunction indicator and the bulletin's listed transmission DTCs. The symptom alone does not select a valve body, CDF cylinder, or complete transmission.
Common Symptoms
- Harsh engagement
- Delayed engagement
- Harsh shift
- Delayed shift
- Malfunction indicator with a bulletin-listed transmission DTC
How to Fix
Have a Ford/Lincoln-capable technician confirm the transmission and build date, retrieve PCM/TCM faults, and follow TSB 22-2428 in order. The bulletin begins with available PCM/TCM programming and an adaptive-learning drive cycle, then uses the stored faults and clutch behavior to select an accelerated main-control break-in routine. If the condition remains, the procedure can require main-control overhaul and, only after the bulletin's later tests fail, condition-specific internal transmission repair. Parts and coverage must be selected by VIN and the actual failed step; this record intentionally has no buy link.
Owner tips & cautions
- TipRecord the exact shift or engagement event and ask for the PCM/TCM fault report plus the TSB decision-tree step that failed before approving internal transmission work.
- WarningDo not order a valve body or CDF part from harsh shifting alone; Ford's procedure can resolve the condition through programming, adaptive learning, or clutch cycling before parts are selected.
Sources for this issue (1)
Nautilus models built on or before March 11, 2021 with the 8F35 8-speed automatic commonly exhibit a shudder, buck, hesitation, or jerk while accelerating from a stop up to about 35 mph (57 km/h). Ford Technical Service Bulletin 21-2389 (superseding 21-2081) attributes the condition primarily to PCM/transmission solenoid control software rather than internal mechanical wear, though severe untreated cases progressed to harsh shifting and, in a minority of CarComplaints reports, complete transmission failure. This is the single most-complained-about Nautilus problem and is the subject of a Chimicles Schwartz Kriner class-action investigation covering 2019-2021 Edge/Nautilus 8F35 vehicles.
Common Symptoms
- Shudder or vibration felt through the floor while accelerating from a stop
- Bucking, jerking, or lurching at low speed (up to ~35 mph)
- Hesitation or harsh engagement when shifting into low gears
- Surging during light-throttle cruise
- In severe cases, slipping or transmission warning light
How to Fix
First-line fix per TSB 21-2389 is to reprogram the PCM with the latest software level and update the transmission solenoid (adaptive) strategy (about 0.9 hours labor, typically covered under the 6yr/70k powertrain warranty). If the shudder persists after reprogramming, the shop should inspect for a failing torque converter, worn clutch packs, or contaminated fluid and replace as needed. A transmission fluid service with the correct Mercon ULV is recommended at the same time.
What you need to fix it
Only diagnosis- and fitment-reviewed repair parts are linked here.
- Motorcraft MERCON ULV automatic transmission fluid XT-12-QULV, 1 quartOEMXT-12-QULV
Drain/fill a confirmed 8F35 that specifies MERCON ULV after fluid-condition and service diagnosis Fitment/availability: Live direct Add to Cart page identifies genuine Ford XT-12-QULV by exact part number and quart size. Confirm 2.0L 8F3…
- Genuine Ford JM5Z-7902-FTC 8F35 torque converterOEMJM5Z-7902-FTC
Replace a converter proven failed by post-programming 8F35 slip/pressure/contamination diagnosis Fitment/availability: Direct retailer item page identifies JM5Z-7902-FTC, Nautilus 2.0L/8F35 description, supersession of JM5Z-7902-B/-F, pr…
As an Amazon Associate, we earn from qualifying purchases; other part links may also earn au7o a commission. Confirm fitment by VIN before buying.
Sources for this issue (4)
- 8F35 Transmission - Shudder/Buck/Jerk While Driving Up To 35 MPH - 2019-2021 Ford Edge & Lincoln Nautilus (TSB PDF)tsb
- 8F35 Transmission Shudder/Buck/Jerk - 2019-2021 Ford Edge & Lincoln Nautilusarticle
- 2019-2021 Lincoln Nautilus & Ford Edge Transmission Class Action Investigationforum
- 2019 Lincoln Nautilus Harsh Shifting Complaints - CarComplaintsarticle
P0731 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 P0731 mean on a Lincoln?
P0731 stands for "Gear 1 Incorrect Ratio." This code means the Transmission/Powertrain Control Module detected an incorrect gear ratio in 1st gear. The module compares input (engine/turbine) speed to output shaft speed; when the car is commanded into 1st but the calculated ratio doesn't match the expected value, P0731 sets. This points to slipping, an incorrect shift, or a hydraulic/mechanical problem rather than just an electrical fault. You may feel slipping, harsh or delayed engagement, or the transmission may go into a limited 'limp' mode. On Lincoln it is documented across 2 models: Aviator, Nautilus.
What are the most common causes of P0731?
The most common causes of P0731 are: Low or degraded/burnt transmission fluid, Slipping clutch packs or worn friction components, Stuck or faulty shift solenoid affecting 1st gear, Internal hydraulic leak / valve body fault, Worn or failing torque converter, Faulty input or output speed sensor, Mechanical wear (planetary gears, bands) inside the transmission. The specific cause varies by vehicle.
How much does it cost to fix P0731 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.
Looking for P0731 on a different make?
View P0731 across all makes →Content compiled with AI assistance using NHTSA complaints, TSBs, and owner reports. May contain errors. Always verify with your vehicle's service manual.