OBD-II trouble code
P2168: Throttle/Pedal Position Sensor 'F' Maximum Stop Performance
The full-travel check failed on the 'F' channel — the last slot the standard enumeration allocates to this family. Six position channels is a great deal of position sensing for one engine, so counting the channels your vehicle actually reports is the cheapest and most decisive first step on this particular code.
Quick facts
- System
- Powertrain
- Category
- Throttle / Idle
- Severity
- High severity
- Drivable
- Usually safe to drive short-term
- Repair cost range
- $0 – $1,600
- DIY difficulty
- Intermediate DIY
Part of a 6-code family
P2168 is one of 6 codes covering throttle/pedal position sensor maximum stop performance. The letter is the slot number your manufacturer assigned — it is not a physical difference, and the same letter means different things on different makes. The diagnosis is the same for every code in the family.
Read the full guide for this family →Browse every code in P2100–P2199, or start from the full code library.
What does P2168 mean?
P2168 sets when the 'F' position channel reports a reading at the wide-open mechanical stop that the module will not accept.
Drive-by-wire systems hold two learned references for travel. One describes fully closed and released, the other fully open and fully depressed, and the module uses them to convert a raw sensor voltage into a percentage of available travel. This code is about the open reference.
P2168 is the sixth and final address in this family, which makes it the end of the enumeration rather than just another letter. That matters for one practical reason: there is no 'G' to fall back on, so if a vehicle genuinely reports six position channels, every slot the standard provides is in use. Six channels is not a common arrangement. The mainstream layout is four — two redundant tracks inside the accelerator pedal assembly and two inside the electronic throttle body. Getting to six means the vehicle carries a third track on one of those assemblies, or a second throttle assembly of its own, or a separate demand input wired for a driver assistance, adaptive cruise or drivetrain control function that wants to read pedal demand without borrowing the main pair.
So the first job on this code is arithmetic rather than testing. Open the live data list and count how many distinct throttle or pedal position parameters the module publishes. If the answer is four, the code is describing something that is not there, and no part will change that. If the answer is six, the code is describing a real channel and the rest of the page applies.
When the count is short, there are two ordinary explanations. A generic scan tool can match a manufacturer-specific code number against a standard definition table and print a channel the vehicle never set in those terms, so a second reading with manufacturer-level coverage is worth the trouble before anything is ordered. And a control module is enabled by its calibration rather than by what is plugged into it, so a module programmed for a better-equipped variant will keep looking for an input the car does not have — an unconfigured replacement, a used module from another trim, or a software update that did not complete all produce exactly this.
There is also a quick way to sort a real channel onto the correct side of the system without opening a wiring diagram. Turn the key on without starting, keep everyone off the pedal, and watch which position parameters move during the module's self-test sweep. Those channels live on the throttle body, because the module can move them by itself. The channels that only respond when the pedal moves live on the pedal assembly. On this code that single observation usually decides whether the expensive part under consideration is a throttle body or a pedal assembly.
Where the channel exists and has genuinely failed the check, the causes are the family's. Something physically limiting travel, a signal path that measures perfectly at rest and falls short at the top of the range, or a stored reference that no longer matches the hardware after a replacement, a reflash or a battery disconnection.
Carbon in the throttle bore is not on that list. Deposits keep a plate from closing, not from opening, which is why they dominate the minimum-stop codes and have little to do with this one.
The letter itself carries no cross-industry meaning. It is a slot index the manufacturer assigned, and the wiring diagram for your exact year, make, model and engine is the only authority on which physical sensor it names.
Common causes
- Module calibration for a variant with more position channels than the vehicle physically carries
- Replacement or used control module never configured to this vehicle identification number
- Generic scan tool printing a manufacturer-specific code against a standard definition table
- Software update that did not complete, leaving the module expecting inputs that are absent
- Worn or drifted 'F' sensor track at the upper end of its range, where that channel exists
- High resistance in the 'F' signal circuit capping its voltage at full travel but not at rest
- Corroded, spread or backed-out terminal on the 'F' pin of the connector
- Floor mat, failed mat retaining clip or a loose object limiting accelerator travel
- Damaged or displaced pedal stop preventing the pedal reaching the floor
- Throttle plate mechanically obstructed at the open end of its travel
- Relearn procedure skipped after a pedal assembly, throttle body or sensor replacement
- Adaptations lost to a battery disconnection or module reflash with no relearn afterwards
Symptoms
- Reduced engine power warning with the upper part of the throttle range unavailable
- Perfectly normal driving up to part throttle and nothing beyond it
- Check engine light that first appeared during a hard merge rather than at start-up
- Idle quality and low-speed manners completely unaffected
- Fewer position channels visible in live data than the code implies
- Code that appeared immediately after a module was replaced, coded or updated
- One position parameter reading a fixed value with no response to pedal movement
- Limp mode that clears on restart and returns the next time full power is asked for
- Additional throttle or pedal position codes stored at the same time
- Cruise control or adaptive cruise refusing to engage
Diagnostic steps
- 1.Count the throttle and pedal position parameters the module publishes in live data before doing anything else. Four is the mainstream arrangement; a code naming a sixth channel on a four-channel car is not describing a part you can buy.
- 2.Re-read the code with a second scan tool that has manufacturer-level coverage for the make, to rule out a generic definition table being applied to a manufacturer-specific number.
- 3.Ask what work the vehicle has had recently. A module replaced, coded or updated shortly before the code appeared moves configuration to the top of the list and hardware to the bottom.
- 4.Verify the module's part number, calibration and software level against the manufacturer's specification for this vehicle identification number.
- 5.With the key on and the engine off and nobody touching the pedal, watch which position channels move during the self-test sweep. Those are throttle body channels; the rest are pedal channels.
- 6.Check under the accelerator pedal for a bunched floor mat, a failed mat clip or a loose object. It costs nothing, and an obstructed pedal is a hazard regardless of the code.
- 7.Test the battery and charging system. Low system voltage limits actuator travel and fails the same check a mechanical fault would.
- 8.Graph every position channel together while the pedal is pressed slowly to the floor, looking for the 'F' trace to stop climbing before the others do.
- 9.Compare the 'F' reading at full travel against the figure in service data rather than against what looks plausible on the screen.
- 10.Perform a voltage drop test on the 'F' signal and ground circuits with the channel held at full travel. A measurement taken at rest will not find this fault.
- 11.Run the manufacturer's throttle and pedal relearn procedure, then retest before condemning any component.
- 12.Confirm from the wiring diagram which physical sensor the 'F' index refers to on this exact year, make, model and engine before ordering a part.
Repair cost
$0 – $1,600
Diagnosis runs $110 to $250 and on this code most of that fee buys a channel count and a configuration check rather than a test result. Correcting a module's coding or software level is $90 to $300 where a shop has the right access; replacing a module that was never the problem is $600 to $1,600. A trapped floor mat or a skipped relearn costs nothing in parts. Connector and wiring repair is $100 to $400. An accelerator pedal assembly is $160 to $500 fitted and an electronic throttle body $280 to $900 fitted, with dual-assembly and performance applications above that.
Estimate your repair
Run the numbers for your vehicle
Open the Repair Cost Estimator with control module replacement & programming preselected. Adjust labor rate and vehicle category to fit your situation.
DIY vs shop
This is an intermediate DIY job. It usually involves diagnostic steps, specialty parts, and some careful work in tight spaces. If you have the tools and a service manual or trustworthy video for your specific vehicle, it is achievable in a weekend. Otherwise, a competent independent shop will be faster.