P0731 on Ford
Gear 1 Incorrect Ratio
P0731 on Ford vehicles indicates gear 1 incorrect ratio. Au7o has documented this code across 2 Ford models — most commonly on F-150, Transit. 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. Typical repair costs on Ford range from $150 to $4,500, depending on the specific model and root cause.
Common Causes of P0731
- •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
P0731 on Ford by Model
Ford F-150(2 issues)
- 10R80 10-speed transmission harsh/erratic shifting and torque-converter shudder2017-2023
The 10R80 10-speed automatic (introduced on the 2017 F-150) is widely reported to shift harshly: jerking, clunking, banging on the 1-2 and 2-3 shifts, hesitation, gear hunting, and occasional limp-mode with a 'Transmission Not in Park' or 'drive mode not available' message. Many trucks also exhibit a torque-converter lockup-clutch shudder felt as a vibration around 30-45 mph. Root causes traced in later TSBs include adaptive-calibration mismatch during break-in, CDF drum bushing migration, and valve-body bore wear/scoring. A class action (O'Connor v. Ford, N.D. Illinois) covers the defect.
- 6R80 6-Speed Automatic Harsh 1-2 Upshift / Erratic Shifting and Lead-Frame Solenoid Body Failure2009-2017
The 6R80 six-speed automatic (2009-2017 F-150) is generally durable but is widely reported for a harsh, banging 1-2 upshift and erratic/flaring shifts, with thousands of NHTSA complaints. The internal solenoid body 'lead frame' (the mechatronic wiring carrier) can crack or develop failing solenoid calibration, and the adapt strategy struggles to relearn after service. The classic symptom is a 1-2 shift so abrupt owners describe it as a jolt that could 'knock a cup of coffee out of your hand.' Towing, worn fluid, and never-serviced 'lifetime' fluid accelerate the problem. It is a top transmission search for this generation.
Ford Transit(1 issue)
- 10R80 (10-speed) Harsh/Delayed Shifts and Shudder (Software/Valve Body Related)2020-2024
Later Transits equipped with the 10R80 10-speed automatic have documented owner complaints of harsh 1-2/2-3 shifts, delayed engagement, and occasional shudder. Ford has issued multiple service communications/TSBs across Ford platforms using the 10R80 addressing shift quality via PCM/TCM calibration updates and, in some cases, valve body service. Drivers often describe banging into gear, flare, or hesitation when pulling into traffic.
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View P0731 across all makes →Frequently Asked Questions
What does P0731 mean on Ford?▼
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 Ford specifically, this code is documented across 2 models.
What causes P0731 on Ford vehicles?▼
Common causes on Ford: 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. Specific causes vary by model and year — see the per-model sections below.
How much does it cost to fix P0731 on a Ford?▼
Repair costs on Ford range from $150 to $4,500, depending on the specific model and root cause.
Which Ford models have P0731 documented?▼
Au7o has documented P0731 on 2 Ford models: F-150, Transit.