P0729 on Ford
Gear 6 Incorrect Ratio
P0729 on Ford vehicles indicates gear 6 incorrect ratio. Au7o has documented this code across 2 Ford models — most commonly on F-150, Fiesta. P0729 means the transmission control system detected an incorrect gear ratio in 6th gear — the computer compares input shaft speed to output shaft speed and found the resulting ratio doesn't match what 6th gear should produce. This usually indicates the transmission is slipping in that gear, a clutch or band isn't holding, or a hydraulic/solenoid control problem is preventing proper engagement. You may feel slipping, flaring RPM, harsh shifts, or the transmission dropping into limp mode. Low fluid and worn internal components are frequent contributors. Typical repair costs on Ford range from $150 to $4,500, depending on the specific model and root cause.
Common Causes of P0729
- •Low or contaminated transmission fluid
- •Worn or slipping clutches/bands inside the transmission
- •Faulty shift solenoid or pressure control solenoid
- •Valve body wear or sticking valves
- •Failing torque converter
- •Internal mechanical wear or damage
- •Speed sensor fault giving incorrect ratio calculation
P0729 on Ford by Model
Ford F-150(1 issue)
- 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.
Ford Fiesta(1 issue)
- DPS6 PowerShift Dual-Clutch Transmission Shudder, Slipping, and Failure2011-2019
The Ford Fiesta equipped with the DPS6 PowerShift dual-clutch automatic transmission is one of the most complained-about vehicles in recent history. The dry dual-clutch design causes severe shuddering, jerking, hesitation, and complete loss of power during acceleration. The clutch plates overheat and wear prematurely, often before 50,000 miles. The Transmission Control Module (TCM) software frequently fails to adapt properly, causing delayed shifts, harsh engagement, and rollback on hills. Ford faced a class-action lawsuit involving nearly 1.5 million vehicles and a federal settlement was reached.
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View P0729 across all makes →Frequently Asked Questions
What does P0729 mean on Ford?▼
P0729 stands for "Gear 6 Incorrect Ratio." P0729 means the transmission control system detected an incorrect gear ratio in 6th gear — the computer compares input shaft speed to output shaft speed and found the resulting ratio doesn't match what 6th gear should produce. This usually indicates the transmission is slipping in that gear, a clutch or band isn't holding, or a hydraulic/solenoid control problem is preventing proper engagement. You may feel slipping, flaring RPM, harsh shifts, or the transmission dropping into limp mode. Low fluid and worn internal components are frequent contributors. On Ford specifically, this code is documented across 2 models.
What causes P0729 on Ford vehicles?▼
Common causes on Ford: Low or contaminated transmission fluid, Worn or slipping clutches/bands inside the transmission, Faulty shift solenoid or pressure control solenoid, Valve body wear or sticking valves, Failing torque converter. Specific causes vary by model and year — see the per-model sections below.
How much does it cost to fix P0729 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 P0729 documented?▼
Au7o has documented P0729 on 2 Ford models: F-150, Fiesta.