03-02-2025
11 min.
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P2163 Throttle/Pedal Position Sensor "A" Maximum Stop Performance

The P2163 Throttle/Pedal Position Sensor "A" Maximum Stop Performance diagnostic trouble code indicates that the vehicle's Engine Control Module (ECM/PCM) has detected a problem with the expected maximum position or maximum-stop performance of Throttle/Pedal Position Sensor "A".

In simple terms, the vehicle's computer is monitoring the accelerator pedal or electronic throttle system and has determined that Sensor A is not reaching, reporting, or responding to its expected maximum position correctly.

This code is related to the vehicle's electronic throttle control system, which allows the ECM to determine how much engine power the driver is requesting.

Depending on the vehicle, Sensor A may be associated with:

Accelerator pedal position sensor
Electronic throttle body
Throttle position sensor
Throttle actuator system
Wiring and connectors
ECM/PCM

The exact component represented by Sensor "A" varies by manufacturer.

P2163 can cause reduced engine power, poor throttle response, or fail-safe/limp mode operation because the ECM must receive reliable accelerator and throttle-position information.

What Does P2163 Mean?

P2163 generally means that the ECM/PCM has detected an abnormal condition involving the maximum-stop position of Throttle/Pedal Position Sensor A.

Modern electronic throttle systems commonly use multiple position sensors for redundancy and safety.

A typical system can include:

Accelerator pedal
Pedal Position Sensor A
Pedal Position Sensor B
Electronic throttle body
Throttle Position Sensors
Throttle actuator motor
ECM/PCM
Reference-voltage circuit
Sensor-ground circuit
Signal circuits

As the accelerator pedal is pressed or the throttle is commanded toward its maximum position, the ECM expects the sensor signals to reach predetermined values.

If Sensor A does not behave as expected, P2163 may be stored.

What Is Throttle/Pedal Position Sensor "A"?

Throttle/Pedal Position Sensor A is one of the position signals used by the electronic throttle-control system.

Depending on the vehicle design, the sensor can be located:

Inside the accelerator pedal assembly
Inside the electronic throttle body
As part of a throttle-position sensor assembly

Many modern accelerator pedals contain two integrated position sensors.

The ECM compares their signals to verify that the driver's accelerator request is accurate.

For example, the two sensors may produce different but predictable voltage ranges. The ECM continuously checks their relationship.

The letter "A" does not identify an identical physical location on every vehicle. Manufacturer-specific wiring diagrams and service information are required to determine exactly which sensor circuit is being monitored.

What Does "Maximum Stop Performance" Mean?

The term maximum stop performance refers to how the position sensor behaves when the accelerator pedal or throttle reaches its maximum mechanical or commanded travel.

The ECM expects the sensor to produce a specific signal at that point.

A fault can occur if:

The sensor does not reach the expected maximum value.
The signal stops increasing too early.
The sensor output is outside the expected range.
The signal becomes intermittent near maximum travel.
Mechanical movement is restricted.
The sensor has lost its calibration.
The wiring introduces excessive resistance.

Therefore, P2163 does not automatically mean that the accelerator pedal is physically stuck.

The problem may be electrical, electronic, mechanical, or calibration-related.

Symptoms of P2163

Symptoms depend on the vehicle and severity of the fault.

Check Engine Light

The most common symptom is an illuminated Check Engine Light.

Reduced Engine Power

The ECM may limit throttle operation as a safety measure.

The vehicle may feel:

Weak
Slow to accelerate
Restricted
Unresponsive

Limp or Fail-Safe Mode

The vehicle may enter a reduced-power mode.

Possible limitations include:

Limited throttle opening
Restricted engine RPM
Reduced acceleration
Reduced vehicle speed

Poor Throttle Response

The accelerator pedal may not respond normally.

Hesitation During Acceleration

The engine may hesitate when the driver presses the accelerator.

Limited Maximum Speed

The vehicle may be unable to reach its normal engine or road speed.

Surging or Irregular Throttle Response

An intermittent sensor signal can sometimes cause inconsistent throttle behavior.

Reduced Fuel Economy

Incorrect throttle-position information can affect engine operation and efficiency.

Warning Messages

Some vehicles may display:

Reduced Engine Power
Electronic Throttle Control fault
Throttle Control System fault
Engine Power Limited
Service Engine Soon

Common Causes of P2163

Several problems can cause this diagnostic trouble code.

Faulty Accelerator Pedal Position Sensor

If Sensor A is integrated into the accelerator pedal assembly, the sensor can wear or fail internally.

Possible failures include:

Incorrect maximum signal
Signal dropout
Internal wear
Intermittent output
Incorrect voltage
Failure to reach the expected maximum position

On many vehicles, the sensor is not separately replaceable and the complete pedal assembly must be replaced.

Faulty Electronic Throttle Body

If Sensor A refers to a throttle-position sensor within the electronic throttle body, the throttle body can be the source of the fault.

Possible problems include:

Internal sensor failure
Throttle actuator failure
Mechanical binding
Internal electrical problems
Damaged throttle-position circuitry

Dirty Throttle Body

Carbon deposits can interfere with throttle movement.

Heavy buildup may cause:

Restricted throttle movement
Incorrect throttle-position readings
Improper throttle adaptation
Slow throttle response

Cleaning the throttle body may help when contamination is confirmed, but cleaning alone will not repair a failed sensor.

Damaged Wiring

The Sensor A signal depends on a properly functioning electrical circuit.

Possible wiring problems include:

Broken wires
Chafed insulation
Short circuits
Open circuits
High resistance
Heat damage

Loose or Corroded Connector

A poor electrical connection can alter the sensor signal.

Possible causes include:

Loose terminals
Corrosion
Water intrusion
Bent pins
Poor terminal tension

Incorrect Sensor Calibration

Some vehicles require an accelerator-pedal or electronic-throttle relearn after certain repairs.

If the learned maximum position does not correspond to the actual sensor position, P2163 may occur.

Mechanical Obstruction

A physical obstruction can prevent the accelerator pedal or throttle mechanism from reaching its expected maximum position.

Possible causes include:

Incorrect floor mat placement
Foreign objects
Damaged pedal
Bent components
Throttle mechanism damage

The pedal should be able to move smoothly through its complete range.

Low System Voltage

Electronic throttle systems require stable electrical power.

Problems with:

Battery voltage
Alternator output
Grounds
Electrical connections

can interfere with sensor readings and throttle operation.

ECM/PCM Problem

An ECM/PCM fault is possible, but it is generally less common than:

Sensor failure
Wiring problems
Connector problems
Throttle-body faults
Calibration issues

The ECM should not be replaced without proper circuit diagnosis.

Vehicles Commonly Affected by P2163

P2163 can occur on many vehicles using electronic throttle control and accelerator-pedal position sensors.

Examples can include:

Ford F-150
Ford Focus
Ford Fusion
Ford Escape
Ford Explorer
Ford Mustang
Chevrolet Silverado
Chevrolet Tahoe
Chevrolet Suburban
Chevrolet Malibu
Chevrolet Cruze
GMC Sierra
GMC Yukon
Cadillac Escalade
Dodge Ram
Dodge Charger
Dodge Challenger
Jeep Wrangler
Jeep Grand Cherokee
Chrysler 300
Toyota Camry
Toyota Corolla
Toyota Highlander
Toyota RAV4
Nissan Altima
Nissan Rogue
Nissan Pathfinder
Honda Accord
Honda Civic
Honda CR-V
Volkswagen Golf
Volkswagen Passat
Audi A4
BMW 3 Series
Mercedes-Benz C-Class

This is not a complete vehicle application list.

Important: P2163 is a generic OBD-II diagnostic code. The exact meaning of Sensor "A," the component being monitored, electrical specifications, and diagnostic procedure can vary between manufacturers and model years.

How Is P2163 Diagnosed?

A professional diagnostic scanner and vehicle-specific service information should be used.

Scan for Additional Trouble Codes

First, scan the ECM/PCM for related codes, including:

Throttle-position codes
Accelerator-pedal sensor codes
Electronic throttle-control codes
Throttle actuator codes
Sensor correlation codes
Low-voltage codes
Communication codes

Additional codes can make diagnosis much easier.

Check Live Sensor Data

Monitor:

Throttle/Pedal Position Sensor A
Throttle/Pedal Position Sensor B
Accelerator pedal percentage
Throttle position
Commanded throttle angle
Actual throttle angle
Sensor voltage

Sensor A should change smoothly as the accelerator pedal or throttle moves.

An abnormal signal near maximum travel can be particularly important when diagnosing P2163.

Inspect the Accelerator Pedal

If Sensor A is located in the pedal assembly, inspect:

Pedal movement
Physical damage
Foreign objects
Floor mat interference
Wiring
Electrical connector

The pedal should move smoothly from its rest position to maximum travel.

Inspect the Throttle Body

If Sensor A is associated with the electronic throttle body, inspect it for:

Carbon buildup
Throttle plate binding
Physical damage
Electrical connector problems
Actuator problems

The throttle should be inspected according to the manufacturer's procedure.

Inspect Wiring and Connectors

Check the Sensor A circuit for:

Open circuits
Short circuits
High resistance
Damaged wiring
Corrosion
Loose terminals
Water intrusion
Poor grounds

Electrical readings should be compared with manufacturer specifications.

Check Reference Voltage and Ground

Position sensors commonly use:

Reference voltage
Sensor ground
Signal circuit

The technician should verify that the reference voltage and ground are stable.

A missing reference voltage can affect multiple sensors and may indicate a larger electrical problem.

Perform a Sensor Sweep Test

The sensor should produce a smooth output throughout its operating range.

A faulty sensor may:

Jump suddenly
Drop out
Stop increasing
Become intermittent
Fail to reach its expected maximum value

This type of test can help distinguish a sensor problem from a mechanical or wiring problem.

Check for Relearn or Adaptation Requirements

Some vehicles require an electronic procedure after:

Accelerator pedal replacement
Throttle-body replacement
Battery replacement or disconnection
Throttle cleaning
ECM replacement

Possible procedures include:

Accelerator pedal position relearn
Throttle-position relearn
Electronic throttle adaptation
Idle relearn

The correct procedure is manufacturer-specific.

How to Fix P2163

The correct repair depends on the confirmed cause.

Replace the Accelerator Pedal Assembly

If Sensor A is integrated into the accelerator pedal and testing confirms a sensor fault, the complete pedal assembly may need to be replaced.

Replace or Repair the Throttle Body

If the throttle-position sensor or actuator is defective, the electronic throttle body may need replacement or an approved repair.

Clean the Throttle Body

If carbon buildup is preventing correct throttle movement, cleaning may resolve the problem.

The manufacturer's cleaning procedure should be followed because electronic throttle bodies can be damaged by improper handling.

Repair Damaged Wiring

Possible repairs include:

Replacing damaged wires
Repairing approved harness sections
Correcting wiring routing
Restoring insulation
Repairing grounds

Repair Electrical Connectors

Connector repairs may include:

Terminal replacement
Connector replacement
Corrosion repair
Terminal-tension correction

Perform the Required Relearn

If the manufacturer requires a throttle or accelerator-pedal relearn, it should be performed after the repair.

A relearn may be necessary even when the replacement component itself is functioning correctly.

Repair Charging-System Problems

If unstable voltage contributed to the fault, inspect and repair:

Battery
Alternator
Battery terminals
Engine grounds
Charging-system wiring

Repair or Replace the ECM/PCM

The ECM/PCM should only be considered after the sensor, wiring, connectors, throttle system, reference voltage, grounds, and calibration have been properly checked.

What Happens If P2163 Is Ignored?

Ignoring P2163 can lead to continued or worsening throttle-control problems.

Possible consequences include:

Reduced engine power
Poor acceleration
Limp mode
Unpredictable throttle response
Restricted vehicle performance
Difficulty accelerating when needed
Possible fail-safe operation

Because the electronic throttle system controls engine power, repeatedly clearing the code without fixing the underlying problem is not recommended.

Can You Drive With P2163?

A vehicle with P2163 may still start and drive normally if the ECM has not activated a reduced-power strategy.

However, continued normal driving is not recommended if the vehicle has severe hesitation, reduced acceleration, limp mode, or unpredictable throttle response.

If a Reduced Engine Power or electronic throttle warning appears, the vehicle should be inspected as soon as possible.

A throttle or accelerator-pedal sensor fault can cause the ECM to unexpectedly limit engine power.

Is P2163 a Serious Code?

P2163 should generally be considered a moderate-to-serious diagnostic trouble code.

The primary concern is the reliability of the vehicle's electronic throttle-control system.

The severity is higher if the vehicle:

Enters limp mode
Loses acceleration
Has intermittent throttle response
Displays multiple throttle-related codes
Experiences sudden loss of engine power

P2163 is not normally associated with immediate internal engine damage, but it can affect the vehicle's ability to deliver power when requested.

How to Prevent P2163

Electronic sensor failures cannot always be prevented, but related problems can often be reduced.

Recommended practices include:

Keep the accelerator pedal area free of objects.
Make sure floor mats cannot interfere with pedal movement.
Keep throttle and pedal connectors dry.
Repair damaged wiring promptly.
Maintain the battery and charging system.
Avoid modifying electronic throttle-control wiring.
Keep the throttle body clean when required.
Follow manufacturer maintenance recommendations.
Perform required throttle or pedal relearn procedures after repairs.
Address Check Engine Light warnings promptly.

P2163 vs. Related Throttle and Pedal Codes

Code	General Description
P2163	Throttle/Pedal Position Sensor "A" Maximum Stop Performance
P2164	Throttle/Pedal Position Sensor "B" Maximum Stop Performance
P0121	Throttle/Pedal Position Sensor "A" Range/Performance
P0122	Throttle/Pedal Position Sensor "A" Circuit Low
P0123	Throttle/Pedal Position Sensor "A" Circuit High
P0220	Throttle/Pedal Position Sensor "B" Circuit Malfunction
P0221	Throttle/Pedal Position Sensor "B" Range/Performance
P0222	Throttle/Pedal Position Sensor "B" Circuit Low
P0223	Throttle/Pedal Position Sensor "B" Circuit High
P2135	Throttle/Pedal Position Sensor A/B Voltage Correlation
P2138	Throttle/Pedal Position Sensor D/E Voltage Correlation

These codes are related to throttle and accelerator-pedal position monitoring, but their exact application can vary by manufacturer.

Final Thoughts

The P2163 Throttle/Pedal Position Sensor "A" Maximum Stop Performance diagnostic trouble code indicates that the vehicle's ECM/PCM has detected that Sensor A is not reaching or reporting its expected maximum position correctly.

Common causes include:

Faulty accelerator-pedal position sensor
Faulty electronic throttle body
Dirty or restricted throttle body
Damaged wiring
Loose or corroded connectors
Incorrect sensor calibration
Mechanical obstruction
Low or unstable system voltage
ECM/PCM problems

A proper diagnosis should include scanning for related codes, checking live accelerator and throttle-position data, inspecting the pedal and throttle body, testing the Sensor A circuit, verifying reference voltage and ground, and performing any required relearn procedure.

Because P2163 can cause reduced engine power or fail-safe throttle operation, it should not simply be cleared and ignored.

Important safety note: The electronic throttle-control system is directly involved in controlling engine power. If the vehicle develops sudden loss of acceleration, severe throttle-response problems, or unpredictable engine behavior, it should be inspected before continued normal driving.