P00AF on Ford: How to Diagnose & Fix
Turbocharger/Supercharger Boost Control "A" Module Performance
2 Ford models · 3 documented issues · $50-$1,600 repair
P00AF on Ford by model: symptoms, diagnosis and fix
Both the 3.5L and 2.7L EcoBoost turbos use exhaust wastegates whose actuator arm/linkage develops play as the bushings wear. The result is a distinctive metallic rattle — most noticeable for the first ~30-60 seconds after a cold start and at light throttle — coming from the turbo area. It is one of the most-searched EcoBoost noises because it sounds alarming but is usually a wear/NVH issue rather than an immediate failure. Ford has issued TSBs: 3.5L wastegate-rattle bulletins and a 2025 TSB for 2024 2.7L trucks (built on/before Oct 4, 2024) where a missing wave spring between the wastegate actuator lever arm and the turbine housing causes the rattle on both turbos.
Common Symptoms
- Metallic rattle from turbo area on cold start (~30-60 sec)
- Rattle at light throttle / tip-in
- Noise diminishes once engine warms
- No performance loss in early stages
How to Fix
Confirm the noise originates at the turbo wastegate (not the timing chain or cam phasers). Per Ford's 2.7L TSB, the repair is installing wave springs between the wastegate actuator lever arms and turbine housings on both turbochargers. For worn 3.5L actuators with excessive arm play, the fix is a new wastegate actuator or, in severe cases, turbocharger replacement under warranty. Often deferred if purely cosmetic noise. Wave-spring/actuator repair typically $150-$600; turbo replacement is far more but usually warranty-covered when within coverage.
Sources for this issue (1)
P0299 sets when actual boost is about 4 psi or more below the commanded value for several seconds, dropping the truck into reduced-power limp mode (orange wrench light). On EcoBoost F-150s the most common causes are NOT the turbos themselves but cheaper upstream parts: a loose or popped cold-side intercooler boot/clamp, a torn orange rubber diaphragm inside the electronic turbocharger bypass (blow-off) valve, and cracked charge-pipe couplers. On 14th-gen (2021+) trucks a specific failure is the plastic upper radiator air deflector warping and blocking the passenger-side turbo intake snorkel, starving that turbo for air (updated part ML3Z-8310-D). Wastegate-actuator sticking can also contribute. Owners frequently — and wrongly — replace turbochargers when a smoke test would have found a hose or the bypass-valve diaphragm.
Common Symptoms
- Sudden loss of power / reduced-power limp mode
- Orange wrench warning light on the dash
- Hissing or whoosh under boost (boost leak)
- Hesitation on hard acceleration
- P0299 stored, sometimes intermittent
How to Fix
Always perform a high-pressure smoke test of the charge-air system before condemning the turbos. Reseat/replace the cold-side intercooler boot and clamps; inspect the electronic bypass valve for a torn diaphragm and replace if leaking. On 2021+ trucks setting P0299 on the passenger bank, inspect the upper radiator air deflector and replace with the updated part (ML3Z-8310-D) if warped. Check wastegate actuators for free movement. Only after leaks, the bypass valve, deflector, and wastegate are ruled out should a turbocharger be considered. A boot/clamp fix can be under $100; a turbo replacement runs into the thousands.
Sources for this issue (1)
The 2.0L EcoBoost uses an electronic wastegate actuator on the turbocharger. Two related failures show up repeatedly: the actuator rod's retaining e-clip goes missing or the linkage works loose, producing a metallic rattle from the turbo area at idle and light throttle; and the electronic actuator itself fails or sticks, so the PCM cannot hold commanded boost and sets an underboost or actuator-performance code with a noticeable flat spot under acceleration. On 2019-2021 Edges the wastegate actuator fault often surfaces as P1464, a code whose description misleads shops toward the A/C system. Left alone, a flapping wastegate flap wears its bushings and eventually requires the whole turbo.
Common Symptoms
- Metallic rattle from the turbo at idle or light throttle
- Check engine light with underboost code
- Flat spot or lack of power on acceleration
- Whistle or hiss under boost
- Limp mode on hard acceleration
- Rattle worse on cold start
How to Fix
Inspect the wastegate actuator rod and the e-clip at the linkage first - a missing clip is cheap to fix and is a known cause of both the rattle and the codes. If the actuator is electrically failed or its commanded-vs-actual position is out of range on a scan tool data log, replace the wastegate actuator assembly (available separately from the turbo on these engines). Check the charge-air plumbing and the turbo bypass valve for leaks before condemning the turbo on an underboost code. Once the flap and bushings are worn enough to be sloppy, the turbocharger itself needs replacement.
Sources for this issue (4)
P00AF 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 P00AF mean on a Ford?
P00AF stands for "Turbocharger/Supercharger Boost Control "A" Module Performance." The PCM uses a boost control module/solenoid ('A') to command the turbocharger or supercharger to the requested boost level. This code sets when the actual boost response does not match the commanded value, indicating the boost control 'A' module or its mechanical linkage is not performing correctly. On Ford it is documented across 2 models: F-150, Edge.
What are the most common causes of P00AF?
The most common causes of P00AF are: Faulty boost control solenoid/module, Sticking wastegate or variable-vane mechanism, Boost/vacuum leak in control lines, Wiring or connector faults, Restricted charge-air path or failing turbo. The specific cause varies by vehicle.
How much does it cost to fix P00AF on a Ford?
Published repair estimates on Ford range from $50 to $1,600 depending on the model and root cause. If an issue mentions a recall or campaign, check your VIN with the manufacturer or NHTSA and confirm eligibility and coverage with a dealer.
Looking for P00AF on a different make?
View P00AF 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.