P2128 OBD-II Trouble Code: Throttle/Pedal Position Sensor/Switch "E" Circuit High Input

Our certified mechanics come to you · Get a fair and transparent estimate upfront

Red-stars EXCELLENT RATING ON

Cost of diagnosing the P2128 code

P2128 is a diagnostic trouble code (DTC) for "Throttle/Pedal Position Sensor/Switch "E" Circuit High Input". This can happen for multiple reasons and a mechanic needs to diagnose the specific cause for this code to be triggered in your situation. Our certified mobile mechanics can come to your home or office to perform the Check Engine Light diagnostic for $0.0 . Once we are able to diagnose the problem, you will be provided with an upfront quote for the recommended fix and receive $20.0 off as a credit towards the repair. All our repairs are backed by our 12-month / 12,000-mile warranty.

Cars Estimate Credit towards follow-up repair Earliest Availability
Ford $0.0 $20.0
Toyota $0.0 $20.0
BMW $0.0 $20.0
SCHEDULE P2128 DIAGNOSTIC Get a fair and transparent estimate upfront

P2128 trouble code definition

The pedal position sensor is used as an input to the engine control module (ECM) to determine the amount of torque requested by the operator. The ECM should receive an input that is within the specifications set by the manufacture. If not, a code P2128 may be set.

What the P2128 code means

The pedal position sensor is a hall effect style of sensor and it should change its voltage according to the angle of the gas pedal assembly. The engine control module will supply the pedal position sensor with what is known as a reference voltage.

Your specific make or model of vehicle will determine whether the voltage increases or decreases as the pedal is depressed. Usually, as the gas pedal is pressed, the pedal position sensor will decrease its produced voltage. There is a specific resistance that should be applied by the pedal position sensor as the accelerator pedal is at rest and when it is depressed.

Resistance acts as a sponge for voltage and absorbs volts as they pass through the circuit. The voltage will exit out of the pedal position sensor and will be sent back to the ECM. The ECM will use this data for engine management such as adjusting the air-fuel ratio and ignition timing. If the ECM determines that the voltage it is receiving is too high, a code P2128 will be set.

What causes the P2128 code?

  • A faulty pedal position sensor
  • Poor electrical connection of the pedal position sensor
  • Open or short circuit condition of wiring associated with the pedal position sensor
  • Faulty ECM

What are the symptoms of the P2128 code?

  • Engine hesitation
  • Check Engine Light illumination
  • Engine lack of acceleration

How does a mechanic diagnose the P2128 code?

  • Inspecting the circuit of the pedal position sensor for poor connections, corrosion, fraying, opens, or shorts

  • Using a scan tool to view the live data of the pedal position sensor while operating the pedal

Common mistakes when diagnosing the P2128 code

There are usually two pedal position sensors used on post-2013 vehicles. It is important to distinguish the two with an appropriate diagram when diagnosing this trouble code. Some mechanics have replaced the wrong sensor unknowingly.

How serious is the P2128 code?

This code is quite serious because the pedal position sensor tells the ECM how much torque the operator is requesting. If it is faulty, in theory and from experience, the sensor may tell the ECM it is at full throttle while only one fourth of the way depressed, which is very dangerous.

What repairs can fix the P2128 code?

  • Repair or replacement of any damaged wiring or electrical connections associated with the pedal position sensor

  • Re-flashing or updating the ECM

  • Replacing the pedal position sensor

Additional comments for consideration regarding the P2128 code

On many late model GM vehicles, there will be an ECM update related to the pedal position sensor. Many mechanics have replaced the pedal position sensor in belief that it will solve the trouble code P2128, while all along it needed an ECM update and not a replacement of the sensor.

Need help with a P2128 code?

YourMechanic offers certified mobile mechanics who will come to your home or office to diagnose and repair your vehicle. Get a quote and book an appointment online or speak to a service advisor at 1-800-701-6230.

Check Engine Light
trouble codes
P2128

No more waiting rooms! Our mechanics will come to you to diagnose and fix the P2128 code.

SCHEDULE P2128 DIAGNOSTIC
Get a $20 credit for the follow-up repair

Recent Check Engine Light is on Inspection reviews

Excellent Rating

(6604)

Rating Summary
6120
230
54
36
164
6120
230
54
36
164
 at YourMechanic

Raymond

37 years of experience
276 reviews
Raymond
37 years of experience
Mercedes-Benz CLK320 V6-3.2L - Check Engine Light is on Inspection - Las Vegas, Nevada
Very knowledgeable and know what to sense what’s wrong . I call Raymond a a hell of a mechanic!!!***
 at YourMechanic

Ronald

41 years of experience
148 reviews
Ronald
41 years of experience
Nissan Versa L4-1.8L - Check Engine Light is on - Conroe, Texas
He was a little late due to a flat tire but called to let me know. He did a great job explaining everything and throughly checking everything. And he solved the mystery of the knocking noise in my car!
 at YourMechanic

John

27 years of experience
10 reviews
John
27 years of experience
Subaru Outback H4-2.5L - Check Engine Light is on Inspection - Port Saint Lucie, Florida
John is not only very nice, but extremely knowledgeable. I feel very fortunate to have him to service my car. He is someone I would recommend to everyone I know. Outstanding!!
 at YourMechanic

Patrick

7 years of experience
55 reviews
Patrick
7 years of experience
Chevrolet Sonic L4-1.8L - Check Engine Light is on Inspection - Duluth, Georgia
Patrick was beyond anything I could've expected. This was my first time using your mechanic. Patrick was 15 minutes early, which was amazing. I was caught in a little bit of traffic, but he did not mind patiently waiting. When I got there, he was pleasant, knowledgeable, and listened to my concerns. Patrick did a full and thorough investigation on my car and its issues. He did not mind explaining what I did not understand multiple times and was very easy to talk to. Thank you again Patrick, keep up the great work!


More related articles

P2635 OBD-II Trouble Code: Fuel Pump ‘A’ Low Flow / Performance
P2635 P2635 Code Definition A P2635 code is a generic powertrain code related to computer output circuit issues. It means that the fuel pump 'A’ is registering a low flow, or one not within the preset parameters. Codes related to...
P0394 OBD-II Trouble Code: Camshaft Position Sensor "B" Circuit Intermittent (Bank 2)
P0394 means the camshaft sensor circuit B that is in engine bank 2 produced an intermittent and incorrect voltage reading
P0003 OBD-II Trouble Code: Fuel Volume Regulator Control Circuit Low
P0003 P0003 trouble code definition The P0003 code is associated with the electrical circuit which connects to your fuel pressure regulator. It also may be related to other codes, such as: P0001, P0002, or P0004. What the P0003 code means...

Related questions

My car has a fuel injector problem, how can I free myself from this problem?

Hi there: In most cases, the symptoms you're describing are related to fuel delivery problems; with components such as the Mass Airflow Sensor, TPS (Throttle Position Sensor), or the throttle body itself being damaged, having faulty connections or simply being...

Check engine Light on and medium consume increased fast

Hello, According to the numbers you have provided, the engine is consuming much more fuel than it is supposed to. You also mention that this began only after your Check Engine Light came on. From your description, it appears that...

OBD support

Hey there. If you have the OBD-2 connector under the dash directly under the steering column, then the ELM327 will work to scan the vehicle after you download the app. I can tell you that this adapter is very cheaply...

How can we help?

Our service team is available 7 days a week, Monday - Friday from 6 AM to 5 PM PST, Saturday - Sunday 7 AM - 4 PM PST.

1 (855) 347-2779 · hi@yourmechanic.com