P1122 Diagnostic Trouble Code – An In-depth Analysis

Vehicle engines have several components and car sensors that work in unison for optimal engine operation. One issue with any of these components will affect the optimal engine operation. This may make the vehicle look like a box of garbage.

If your accelerator feels unresponsive, the chance is there’s an issue with the throttle position sensor. Once this happens on your Nissan, Infiniti, Chevy, or Toyota vehicle, the powertrain control module will log error code P1122.

What does a P1122 code on Chevy and other car models mean, anyway? This article will explain the possible symptoms, causes, diagnostic mistakes, and how to track and fix a P1122 culprit.

p1122 code

What does error code P1122 mean?

Diagnostic trouble code P1122 is a manufacturer-specific trouble code. This means it is not a generic code and does not appear in all car models. Nissan manufacturers define it as Electronic Throttle Control Performance Problem. It is common with Nissan and Infiniti cars. In addition, it also appears on Chevy, Opel, Toyota, and Honda cars.

A P1122 error code means the engine control module has detected abnormally low or high voltage from the electronically controlled throttle actuator. By abnormal, we mean the current voltage falls outside the predefined or expected voltage by the car manufacturer. 

The throttle body is one of the essential components that control the air-fuel input into the engine. It controls the amount of air-fuel mixture that goes into the engine during the combustion process.

On the other hand, the throttle position sensor monitors the throttle body, measures the air-fuel input, and relays the information to the car computer. Older throttle bodies have cables or control linkages that control the opening and closing of the throttle.

This article discusses electronically controlled (newer) throttle actuators. Let’s see the signs of a P1122 on Opel and other car models.

What is the symptom of error code P1122?

The P1122 fault code is an obvious issue with numerous symptoms that alerts the car owner or driver to check and rectify the underlying issues. The common symptoms of a P1122 on Nissan Sunny and other car models are check engine light, hard starting, and little or no throttle response.

Check engine light

The car computer illuminates the check engine light on the dashboard whenever it detects imminent issues with any drivetrain or powertrain component. The engine warning light is one of the common symptoms you’ll notice once the car computer throws a P1122 error code.

Kindly note that several factors aside from a P1122 can trigger the check engine light on the dash. Therefore, it is important to watch out for any of the below signs or conduct a thorough diagnostics before saying you have electronically controlled throttle performance issues.

Hard starting

Since the throttle body and the throttle position sensor controls the air-fuel input into the engine, the sensor can send wrong information to the car computer. If this happens, the car computer may send a limited amount of gas to the engine. As a result, this will cause a hard engine to start.

Unresponsive throttle pedal

 Depending on the actual cause of the P1122 on Toyota Land Cruiser or your respective car models, you may feel little or no throttle response. By default, your vehicle should accelerate when you depress the car pedal. But if the throttle position sensor is bad, the car computer will not communicate with the throttle pedal input.

Loss of engine power

Undoubtedly, a P1122 error code will cause a loss of engine power while driving or when idling. For example, if the throttle position sensor is bad or the throttle body is bad or has carbon buildup, the car will lose power on idle or when driving.

Engine dies at low speed.

Another notable symptom you’ll notice is that the vehicle will often die in traffic or when stopping the vehicle. Although, several other parameters like the spark and injection issues can be the culprit.

Other probable signs of a P1122 on Prius and other car models include

What Causes error code P1122?

Several factors can cause the powertrain control module to register error code P1122 on GM and other car models. Here are the probable causes you should look into when diagnosing the root cause of the problem.

  • A malfunctioning throttle position sensor
  • Worn out throttle body
  • Excessive carbon in the throttle position sensor
  • Bad wires or connectors

How serious is error code P1122?

The P1122 is a severe case because it can lead to little or no throttle response. This can lead to a catastrophic collision if the throttle becomes unresponsive on the highway, especially when overtaking another vehicle. It can also keep you frustrated in a lonely place.

Electric Throttle Control Performance Problem

How to Diagnose error code P1122

If you’re not a gearhead, you’ll need a simplified guide to track and fix the root cause of P1122 on Nissan Tiida or your respective car model. If not, you may end up wrongly throwing money at parts.

Don’t worry; this easy-to-follow walkthrough will guide you through the process. Follow the steps religiously.

Tools and Items Needed

Step 1: Scan the vehicle

Locate the vehicle OBD port underneath the steering wheel and connect your scan tool. Read the registered fault codes. If there’s any other error code besides P1122, track the root cause and rectify it before heading to the next step.

Step 2: Examine the Wiring connections

Open the hood and inspect all the throttle body wiring connections and connectors. Ensure the connectors are properly connected and the wires are in good condition. If you notice any frayed, burnt, damaged wires or loose connectors, fix them to rectify the problem.

Step 3: Clean the throttle body

Locate the throttle body and remove the air duct connected to it. After that, slide the butterfly flange in the throttle and see if there is any carbon buildup. If you see any carbon buildup, clean the throttle body thoroughly and reconnect the disconnected components.

Step 4: Examine the throttle body

Examine the throttle body and see if it has any physical damage. If you notice any physical damage like cracks, replace the entire throttle body.

Step 5: Inspect the throttle position sensor

Test the throttle position sensor to see if it is okay or not. Replace the throttle position sensor (TPS) if the test proves it’s damaged.

Step 6: Contact a service technician.

If all the steps prove abortive or you can’t handle them thoroughly, contact a service mechanic to diagnose and proffer solutions to the problem.

Common P1122 diagnosis mistakes

Here are the common mistakes DIYers can often make when diagnosing a P1122 fault code.

  • Not checking and fixing related troubles
  • Not examining the connectors and wires for damages and loose connections
  • Replacing suspected parts without thorough examinations.

How do you fix P1122? 

As demonstrated above, there are several probable causes of P1122 on the Nissan X trail and other car models. Also, there are probable solutions to rectify the problem. Therefore, here are a few probable solutions needed to rectify the problem.

  • Replace or repair corroded, burnt, or damaged wires and connectors as needed
  • Replace faulty electronic throttle position actuator
  • Clean dirty throttle body
  • Replace defective throttle position sensor
  • Replace malfunctioning ECM (though not likely the cause, but possible).

Approx. Repair Cost

If you want to drive your car to an auto repair shop, the technicians will start with an hour of diagnostics. On average, you should expect to spend between $75 to $150 per hour, depending on your region and the service technician.

After the diagnosis, the auto repair shop can accurately estimate the repair cost of the problem. Then, if you have the technician fix the problem, they’ll add the diagnostic fees to the service charge. Here are the possible replacement or repairs and the cost.

  • Throttle body replacement $200 to $650
  • Cleaning throttle body $75 to $200
  • Throttle position sensor replacement $110 to $200
  • Repairing or replacing frayed, burnt, or damaged wires or corroded connectors is $50 to $200.

Final Words

As indicated already, P1122 is a manufacturer-specific trouble code that means Electronic Throttle Control Performance Problems. The car computer sets the error code once it detects a problem with the electronic throttle control system.

This article has outlined the possible symptoms, causes, severity, and how to track and fix the problem. Follow the simplified walkthrough to track and fix the problem. However, if you don’t trust your gut or you’re not familiar with the underhood working principles, contact a certified technician to resolve the underlying issues.

Osuagwu Solomon

Osuagwu Solomon is a seasoned automotive technician for the past 9 years, and a technical writer. He loves writing about auto professional repair guides, DIY repair guides, and buyer’s guide. After spending six years in the automotive workshop, he decided to impact his knowledge to people aside his domain, and he has achieved this by centering his Automotive writing skills on REPAIRS.

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