P2135: Reasons, Symptoms, Diagnosis, And Repair

P2135: Reasons, Symptoms, Diagnosis, And Repair

Vehicles of today are highly complex machines in comparison to their ancestors. Diagnostic trouble codes are your vehicle’s way of telling you something is wrong under the hood, such as a P2135 error code.

Modern vehicles depend on a bunch of circuits, sensors, and control modules to work properly. Mostly, these electronics have been tasked with the jobs that used to be done by vehicle components manually back in the days.

Thanks to this sort of development, vehicles today are more efficient than they have ever been, also adding to their reliability. But, like any mechanical or electrical equipment, it is not immune to the occasional fault. Many problems of this kind may arise and do so from time to time.

You can use a scan tool to review such problems that your vehicle’s PCM/ECM registers. Events of this magnitude are defined as a Diagnostic Trouble Code, or DTC, such as the P2135 code which defines an issue within a car’s “drive-by-wire” throttle system.

P2135 serves as a reminder that electronic control devices do fail occasionally and it’s completely fine and reparable. Keep reading to learn about trouble code P2135 and how to diagnose and remedy it.

P2135 Code

Error Code P2135 describes a situation where the vehicle’s PCM or Powertrain Control Module (also known as Engine Control Module, or ECM in other vehicles) finds an incorrect and erratic voltage reading sent by the Throttle Position (TP) A or B, actual throttle plate, and accelerator pedal position sensor.

Both TP sensor outputs are expected to stay within close and coherent range of each other; the PCM regularly contrasts the sensor readings to measure their punctuality and efficiency. Based on the throttle plate’s position each Throttle Position transmits a voltage signal to the PCM. The PCM then reads this signal to understand how far the plate has opened.


If one TP sensor gives a half throttle open reading while the other reads full throttle, your vehicle’s PCM will store the P2135 code, as the voltage readings are in no way accurate.

The TP sensor can be found on the throttle body inlet. According to DTC 2135, the voltage reading given by the accelerator position sensor and TP sensor are too far away from each other, making the readings void. Signals from the accelerator position and TP sensors must correlate to one another, or the PCM will set a code.

Similar DTC includes:

  • P2136
  • P2137
  • P2138
  • P2139
  • P2140

Fortunately, troubleshooting for these codes is the same.

Codes Related To P2135

When a vehicle stores one trouble code, it rarely does just one. Multiple related codes are stored at the same time and they can generally be diagnosed and repaired in the same way. This mostly happens because one component of a vehicle may have multiple jobs and one task can be completed by a bunch of parts.

Codes related to P2135 are:

  • P0223 – Throttle position (TP) sensor B/accelerator pedal position (APP) sensor/switch B -high input
  • P0222 – Throttle position (TP) sensor B/accelerator pedal position (APP) sensor / switch B -low input
  • P0220 – Throttle position (TP) sensor B/accelerator pedal position (APP) sensor / switch B -circuit malfunction
  • P0123 – Throttle position (TP) sensor A/accelerator pedal position (APP) sensor / switch A -high input
  • P0122 – Throttle position (TP) sensor A/accelerator pedal position (APP) sensor / switch A -low input
  • P0120 – Throttle position (TP) sensor A/accelerator pedal position (APP) sensor / switch A -circuit malfunction

Throttle Pedal Position And Throttle Position Sensors

Throttle Pedal Position Sensor

The two Throttle Position sensors are joined to the throttle body, a part connected to the engine intake system of a car. Air enters the engine through the throttle blade and it opens wider upon stepping on the accelerator pedal to let more air in. The TP sensor has to monitor how much air the engine gets by telling the computer how open much the throttle blade has opened.

Throttle Pedal Position Sensor Switch

The accelerator pedal position sensors or pedal monitor the volume of fuel the engine gets against how hard the gas pedal is pressed. Learn how to do accelerator pedal position sensor testing in this video.

Related Notes About Code P2135

Different automakers label DTC P2135 in different ways. For instance, P2135 for Nissan and Infiniti cars will mean “throttle position sensor circuit range/performance” while the same code stands for “electronic throttle control system malfunction power management” on vehicles from Hyundai.

Vehicles That Are Most Prone To 2135 Code

DTC P2135 can happen on different cars but some brands are more susceptible to it than others. Here is a list of them:

  • Cadillac
  • Chevrolet (Aveo, Cruze, Malibu, Silverado, Suburban, Tahoe)
  • DAF
  • Datsun (on-DO)
  • Fiat (Ducato)
  • Ford (Expedition, Explorer, F-150, Focus, Fusion, Mondeo)
  • GMC (Envoy, Sierra)
  • Geely (Emgrand X7)
  • Honda (Accord)
  • Hyundai
  • Infiniti (FX35, G35)
  • Jaguar (X-Type)
  • Kia (Sorento)
  • Lifan (X60)
  • Mazda
  • Mercedes-Benz (Sprinter)
  • Mitsubishi (Outlander, Pajero)
  • Nissan (Almera, Juke, Micra, Murano, Note, Qashqai, Sentra, Teana)
  • Opel (Astra, Corsa, Insignia, Mokka)
  • Peugeot (Boxer)
  • Renault
  • Saab
  • Subaru (Forester, Legacy)
  • Toyota
  • Volvo (XC90)
  • GAZelle
  • LADA (Granta, Kalina, Largus, Niva, Priora)
  • UAZ (Hunter, Patriot)
  • VAZ (2114, 2115)

Symptoms Of P2135 Code

If the gas pedal and throttle are not working in harmony, it can give rise to numerous visible issues. If your vehicle’s Check Engine Light comes on but you cannot find any symptoms, chances are, the problem is a bad sensor. Symptoms of car throttle failure are rather noticeable and can be diagnosed by most people with general know-how on electronic systems.

Before we discuss diagnostics, here are the signs that the P2135 throttle sensor position is failing your vehicle:

  • Hesitation or Surging When Accelerating: Your vehicle’s acceleration process should be effortless and smooth every time. If the vehicle is stuttering at this stage, something is surely wrong.
  • Engine Revving When Idling: The throttle might be opening automatically even if you do not have your foot on the gas.
  • High RPMs: On average, the regular RPM of a car should be between 600 to 1000 in an idling state. It will rise when accelerating but will return to its original state quickly.
  • Stalling: An opened throttle that is not doing its job will flood the engine, causing your car to stall. This might be noticeable while accelerating or idling.
  • Check Engine Light Comes On: Car owners dread this little light shining across their dashboard as it can mean a million things. Whenever you see the CEL come on, make sure you take your vehicle to a professional to get it checked.

Possible Causes Of DTC P2135

As modern cars are teeming with wires and sensors, the common reason behind this code is a faulty component. In rare cases, an issue may arise with the throttle control, but the symptoms will give it away when you are driving. All in all, these are some of the top reasons you may be getting DTC P2135 on your vehicle.

  1. Bad PCM: The sensors of the Powertrain Control Module are reading the throttle controls wrong.
  2. Poor Throttle Position Sensors: Although the throttle is working alongside the pedal, it is not showing because the sensors have gone bad.
  3. Faulty Accelerator Position Sensor: The throttle is fine but the sensor observing the pedal may be faulty.
  4. Disturbance in the Throttle Position Sensor: Connections running to the throttle sensor may be damaged, corroded, or extremely short.
  5. Disturbance in the Accelerator Position Sensor: Connections running to the pedal may be damaged, too short, or corroded.

Diagnosis Of Trouble Code P2135

Some points to note about the electronically regulated throttle. This mechanism is extremely sensitive and weak to damage, much more than other systems of your vehicle. All components associated with the system have to be handled with utmost care to avoid damage. Rough handling or one drop and your component is history!

Aside from the accelerator pedal sensor, the component’s remainders are located in the throttle body. You will see a flat plastic cover situated on top of the throttle body if you check. This holds the gears that activate the throttle plate. On the motor, a little metal gear protrudes up through the housing. It drives a significantly bigger “plastic” gear connected to the throttle plate.

The throttle body housing holds the pin that supports and centers the gear while the “thin” plastic cover fits the top pin. If the cover is incorrectly placed in any way, the gear is completely compromised, warranting a throttle body replacement.

With that in mind let’s go over how to diagnose a P2135 code. This process remains the same for most vehicles, regardless of P2135 Ford or P2135 Chevy.

Firstly you have to go online and find the TSBs, or Technical Service Bulletins for your car associated with the trouble code. Customer complaints and/or identified problems issue these TSBs, and the manufacturer or technicians come up with repair processes for them.

Then, check in a service manual or online for a plausible relearn process to reset the vehicle’s computer. For instance, you have to turn on the ignition and wait three seconds on a Nissan. In the following five seconds, press and free the pedal five times. Let it sit for another seven seconds, press down, and hold the pedal for ten seconds.

Diagnosis Process For A P2135 Code

Once that’s done, follow these diagnosis steps as outlined below:

  1. Release the pedal once the Check Engine Light starts blinking. After waiting 10 seconds, press the pedal once more for 10 seconds and let go. Turn off the ignition.
  2. If extra codes like P2135 present themselves, work on those codes first as they are a part of the system and might be directly linked to the storing of code P2135.
  3. Take out the electrical connector from the throttle body and check it carefully for bent or missing terminals. Examine for corrosion. Use a small pocket screwdriver to clean any of that corrosion and reconnect the terminals by applying a little electrical grease on them.
  4. If the connectors of the terminal are bent or have missing pins, don’t worry. You can get a new “pigtail” almost anywhere – online, from a dealer or auto parts store.
  5. Check the throttle body’s top cover for warping or cracks. If there are any, ring up your deal and ask if they can sell only the top cover. The whole throttle body has to be replaced if they say no.
  6. Investigate the accelerator pedal sensor with a voltmeter. It will show 5V for reference and a varying signal next to it. Turn on the key and carefully press down on the pedal. This should increase the voltage from 0.5 to 5.0. Chance it if there is no voltage reading at the signal wire.
  7. Check on the Internet for wire terminal identification on your vehicle’s throttle body. Inspect for power connectivity in the throttle body connector. Have some turn on the key and slowly press down on the pedal. The computer is faulty if there is no power. On the other hand, the throttle body can be marked at fault if there is power.

Common Diagnostic Mistakes

As there are 2 throttle sensors, it is crucial to know which is which and make sure they are returned to their original position. Once again, we suggest you bring your vehicle to a professional for the diagnosis process.

Another common diagnostic mistake is not examining every sensor. The others might still be faulty even if you have narrowed the issue down to one sensor. Be thorough with the troubleshooting so everything is discovered and fixed the first time.

How To Fix Code P2135

Follow the given steps after you have diagnosed the primary reason(s) of DTC P2135 on your vehicle. As always, look into your owner’s manual for factory-specific instructions as they vary from one automaker to another.

Step 1: Check For Additional DTCs

Before starting any diagnostic process for any particular DTC, you have to check for any other diagnostic trouble codes stored by your vehicle. All extra DTCs have to be diagnosed thoroughly before continuing.

Step 2: Check TSBs

Your vehicle may have specific technical service bulletins issued for it. Those will better explain how to repair such situations. Follow the instructions if you find a TSB.

Step 3: Visually Check APP And TPS Wiring

Now inspect the connector and wiring pigtail of your vehicle’s APP and TPS. All connectors must be bend- and corrosion-free. The wiring should not have any obvious damage or fraying. Repair these components as needed.

Step 4: Check Voltage At APP/TPS

Use a multimeter to check the voltage at both the APP and TPS, following the manufacturer’s specification. The readings acquired from such must be within the stated operation ranges (refer to your automaker’s specifications).

Voltage must move smoothly when you depress the vehicle’s accelerator pedal.

Step 5: Replace TPS If Needed

If the correct voltage reading is given at the connection of the wiring harness to the throttle body but P2135 remains, a system relearn has to be done. You should refer to your vehicle manufacturer’s specifications for this procedure.

If this does not fix the issue you are facing, throttle body replacement will be needed.

Unless you are somewhat confident in your automotive DIY skills and know-how, it is best to let a mechanic handle the issue. Otherwise, feel free to address the DTC yourself. Understand the reason behind the code, then find out how to fix it by researching established repairs that apply to the make, model, and brand of your vehicle.

You can also find various auto repair guides and resources online to help you. Alternatively, check out ALLDATA.

What Is Code P2136?

Code P2136 stands for “Throttle Pedal Sensor Voltage Correlation.” This DTC is set by the PCM when it recognizes a problem with its circuitry or sensor. To keep the vehicle operator and the driver protected, the vehicle might jump to limp mode (and learning how to bypass limp mode). In this case, the top speed is 20 mph.

How To Correct This

This code might pop up alongside error code p2135. If it does, this DTC has to be repaired first. The diagnosis and repair of similar error codes are fairly similar so this should not be a problem for you.

  • Replace or repair the PCM
  • Repair or replace the TPS assembly
  • Replace or repair the corroded wires and/or any loose connections at the ECM or TPS
  • Repair or replace any damaged circuitry


Make it a point to consult your car’s owner’s manual before conducting any repair or diagnostic procedure. What works for someone’s vehicle might not be compatible with yours due to the difference between makes and models of cars. The last thing you want to do is worse the situation with an incorrect fix.

When in doubt, reach out to a professional.

Estimated Cost Of Repair

For code P2135, you may have to get one or more of the repairs stated below to resolve the underlying concern. For every potential repair, the cost of repair (estimate) includes the cost of the parts and the cost of labor needed by the mechanics.

  • Accelerator pedal position sensor $130 to $200
  • Throttle position sensor: $170 to $230
  • Wiring repair/replacement: $100 to $1000
  • Throttle body actuator: $570 to $700

Is Code P2135 Serious?

Much like with any trouble code, P2134 should be taken incredibly seriously. When a code like this persists it means that the throttle of your vehicle’s engine is not doing its job, increasing the risk of an unwanted situation. At the very least, it will dent your vehicle’s drivability, thus becoming a bigger problem than what it started as.


In many cases, the P2135 code will trigger a “decreased power” mode where a vehicle’s top speed and output are seriously restricted. The potential risks of this situation lie in not exactly knowing when a car will suddenly enter “limp mode.” Such problems can happen easily while driving at interstate speeds.

In any event, diagnostic trouble codes should be addressed as soon as possible. Not only does this reduce the chances of secondary problems, but it also decreases the possible future costs associated with the repair.

If you do not want to address such problems on your own, book an appointment with a trusted auto shop as quickly as you can.

Throttle/Pedal Position Sensor/Switch A / B Voltage Correlation Facts:

  1. The P2135 code indicates that the Power Control Module (PCM) has detected an erroneous reading regarding the voltages transmitted by the throttle position sensor A or B, the accelerator pedal position sensor, and/or the actual throttle plate.
  2. The PCM expects both throttle position sensor outputs to stay within a logical and fairly close range of one another to test their efficiency and punctuality.
  3. Throttle position sensors and the accelerator position sensor must correlate with each other, or a code such as P2135 will set.
  4. The accelerator position sensor operates in an identical fashion as the throttle position sensor and sends a voltage signal back to the PCM according to how far the pedal is pushed down.
  5. If the voltage readings of the throttle position sensor and the accelerator position sensor vary too much, then a code P2135 will set.
  6. Symptoms of the P2135 code include surge or hesitation when accelerating, revving of the engine when the gas pedal is not pressed, higher than usual RPMs, Check Engine Light illumination, and vehicle may stall out.
  7. A mechanic can diagnose the P2135 code by back-probing the sensors with a multimeter or scan tool, testing the ohm levels of the sensors, and checking TSBs and recalls related to some makes and models for this particular code.
  8. Common mistakes when diagnosing the P2135 code include mixing up throttle position sensors 1 and 2, resulting in the replacement of the wrong sensor.
  9. The vehicle may stall out which can be dangerous if it happens in heavy traffic or when going around turns.
  10. Repairs to fix the P2135 code include replacing one or both throttle position sensors, replacing the accelerator pedal position sensor, or repairing a fault in a circuit such as open, short, corroded wiring, or poor connection.


The throttle sensor of a vehicle plays a vital role in it, so any DTC related to it should not be left unattended, especially P2135. However, if you do not see any problems with revving or acceleration, we recommend resetting the OBD-II sensor to check if it turns the light back on.

A certified mechanic is certainly better equipped to handle such situations. Invest in your vehicle a little at the earliest signs of trouble and you will save yourself a lot of hassle and money in the long run.

Frequently Asked Questions (FAQs)

Here are some popular FAQs:

How To Fix Code P2135

Error code P2135 can be fixed by replacing the accelerator pedal position sensor or replacing the throttle position sensors (one or both). If that doesn’t solve it, you can try fixing the fault in a circuit (accelerator pedal position sensor circuit, throttle position sensor circuit), such as short, open, corroded wiring, or bad connection. Should that not be enough, then repair any faults in the circuit such as open, short, corroded wiring, or poor connection.

What Is Code P2135

Code P2135 stands for Throttle/Pedal Position Sensor/Switch A / B Voltage Correlation.

What Does Code P2135 Mean

If your vehicle stores code P2135, it means the PCM/ECM has found the accelerator pedal position sensor and throttle position sensor to not be producing the required signals. When the PCM/ECM recognized this, it might put the car in a fail-safe condition. This condition restricts throttle opening from 5% to 15%.

Can A Bad TPS Sensor Cause No Start

If a TPS sensor is faulty, the throttle body of your vehicle will not work properly. It won’t close correctly or stay shut which is a big issue. If it remains shut, the engine will not receive air and thus, not start.

How Do You Replace A Throttle Position Sensor

Follow these steps to replace a throttle position sensor – First, detach the battery and disconnect the old sensor. Then, you can take out the mounting screws and remove the old throttle position sensor. Now, place and screw in the new sensor, and reattach the wiring harness. Lastly, you can rejoin the battery cables.

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