Fix the P2138 Chevy Silverado Code with Our Experts!

What does the P2138 Chevy Silverado mean? In short, it’s a diagnostic trouble code that directly hits the correlation of the throttle position sensors.

Now, why does this trouble code take place in our Chevy Silverado? Are there any symptoms to identify the problems? Well, the most common problem can be a lousy accelerator pedal position. Meanwhile, there are other reasons too for triggering the P2138 code.

In this article, we are going to cover all those reasons, symptoms, and simple solutions for this code. Before that, it is important to have a prescribed discussion about the P2138 code first.

Let’s not make any further delay, jump toward the concept straight.

P2138 Chevy Silverado: All About This Diagnostic Trouble Code

It’s pretty clear to us that the P2138 is a diagnostic trouble code. Even the Chevy Silverado models couldn’t escape from it.

However, the P2138 means –

“Throttle/Pedal Position Sensor/Switch D/E Voltage Correlation.”

The main reason for its triggering is when the Engine Control Module of the Chevy Silverado detects a specific signal. This signal is about the disruption in the correlation of sensors, i.e., two throttle position sensors.

The Engine Control Module (ECM) or the Powertrain Control Module (PCM) starts to illuminate because it can’t find the right accelerator position at that time. This type of illumination is most likely a warning light or a throttle blade light. Sometimes, the engine does not accelerate totally when the case becomes extreme.

In easy words, we can say, when you press the gas pedal, the acceleration position sensor delivers a signal to ECM or PCM. Then the throttle position sensors see if the throttle is open or not. The PCM or ECM will cope with the throttle position by getting feedback.

There are two TPS signals, “D” and “E”. Their task is to agree with the pedal position sensors and, of course, with one another as well. If you see they are not agreeing, it means your vehicle is suffering the P2138 diagnosing trouble code.

Peak Reasons And Symptoms For Triggering The P2138 Chevy Silverado

Reasons For Triggering the P2138 Trouble CodeNoticeable Symptoms
If the pedal position sensor is badCar stops responding
Wiring harness of the throttle position sensor is shorted or openEngine stalls and goes into limp mode.
If the electrical connection of the throttle pedal position sensor circuit is poorThe “Pedal feel” seems strange
The electric throttle control actuator is faultyThe engine lacks the power to accelerate
Issues in PCMIncreased fuel consumption

So far, we have acknowledged the P2138 code, but it’s yet to know about its reasons and symptoms. The most common symptom that most users have faced because of this code is the illumination of the check engine warning light.

But the fact is, the symptoms of P2138 do not terminate here. More possible causes and signs can bring this code to light. Let’s have a brief discussion about them below:

Bad Throttle Position Sensor

Whenever the P2138 Chevy Silverado 1500 takes place, a bad throttle position sensor has mostly been the reason. You will get to see this problem if the engine idling speed of your vehicle suddenly gets increased. Or when the accelerator pedal does not respond anymore.

Don’t worry; repairing the pedal position of your Chevrolet can solve the problem instantly.

Shorted Or Open Wiring Harness Of The Throttle Position Sensor

Open and short wiring of the throttle position sensor will surely lead your Chevy Silverado to the P2138 trouble code. At that time, your vehicle’s engine may go limp mode or may even stall.

Just diagnose the pigtails that are connected to the throttle position sensor. If you see any problem, contact the mechanic. In fact, the 2007 Chevy Silverado code P2138 was diagnosed in the same way and then resolved.

Poor Electrical Connection Of The Sensor Circuit

The pedal of your Chevy Silverado will start to seem strange when the P2138 occurs. It’s because of the poor electrical connection of the throttle pedal position sensor circuit. Take help from a service center at that time, and ask if the wiring is a problem or not.

As the 07 Chevy Silverado code P2138 faced some wiring issues, this factor is something to be concerned about.

Bad Electronic Throttle Control Actuator

Your car won’t exceed the low speed even though it accelerates and may stall after a time. This is because a bad electronic throttle control actuator does not allow it to do so. Thus, the smoothness of the vehicle disappears.

If you want your Chevy Silverado to operate like a pro again, get the throttle position sensor repaired right now. Most users got out of their 2011 Chevy Silverado code P2138 by repairing the throttle sensor. So you should also do that if your throttle sensor is faulty.

PCM Issues

The PCM issue is an unavoidable thing in Chevy trucks. It makes the vehicle not run at all. The vehicle stalls or slitters even if it is kept idle. The check engine light also remains on due to this issue.

However, a PCM reflash in your car may solve this problem. Or you can also get some suggestions from your Chevy dealer. Whether it is a 2009 Chevy Silverado 1500 P2138 or a 2006 Chevy Silverado P2138, the PCM issue triggers this code.

Frequently Asked Questions (FAQs)

What causes code P2138?

The P2138 code usually gets triggered when any trouble occurs in the correlation of two throttle position sensors. In times of triggering this error in a Chevrolet Silverado, the Engine Control Module first detects the signal of disruption in the sensors.

How much does it cost to fix the P2138 code?

There is no definite cost to condemn first. It will depend on which component of the throttle control system of your Chevy Silverado has got damaged. Well, diagnosing it will take about one hour first. And also, which auto shop you are taking to, shall decide the cost. Anyways, you can expect to spend $70 to $150.

Is P2138 serious?

No doubt, the P2138 is a major and serious issue for any Chevy Silverado. Since it affects the vehicle’s ability to control the acceleration, it won’t make the vehicle operate anymore. In most cases, the P2138 code makes the Chevrolet’s throttle stick. Afterward, experiencing hazardous conditions and accidents becomes inescapable.


Hopefully, we have transpired an oriented distinction about the P2138 Chevy Silverado. It’s none other than a diagnostic trouble code that tells the users that the throttle position sensors are not agreeing to correlate. The Engine Control Module (ECM) or the Powertrain Control Module (PCM) detects this type of signal in a Chevy Silverado.

Anyways, it’s time to buckle up now as the reasons for triggering the P2138 code are apparent to us. Also, the mentioned symptoms have made us more alert about what could happen when the problem occurs.

This was all. Let us know if you have any queries.

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