P1516 code — how to fix error fast

If you notice a problem with the way your car accelerates and the scanner tool reveals the code P1516, you probably have quite a few questions. First and foremost is getting to know the P1516 code meaning and why it appeared in your car. Knowing how it affects your driving comes right after, so we prepared a detailed guide to tackle all the issues regarding the code.

You can be the judge as to how the code reflects on your vehicle, but only once you’ve gone through this article with all the essential information on how to diagnose it, fix it, and make sure your car drivers smoothly after erasing the code.

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What does the P1516 code mean?

The P1516 code is a generic powertrain code that relates to the electronic throttle control system (ETCS). The code indicates that there is an issue with the throttle actuator control module (TACM) or the throttle actuator control (TAC) system. The TAC system is responsible for receiving input from the accelerator pedal position sensor (APPS) and sending a signal to the engine control module (ECM) to adjust the throttle opening accordingly.

We know – it can be confusing to look at it as a bunch of random codenames and car parts. If you aren’t that much of a car guy, let us put it this way – the electronic throttle control system measures your output on the accelerator pedal and ensures that the throttle body opens accordingly with it.

Back in the day, there was no electrical system in place so the link between the pedal and the throttle body was physical. Still, these days the modernization of cars took its turn and that means it’s time to explore the reasons behind the system’s malfunction.

What causes the P1516 code?

There are several potential reasons behind the activation of code P1516. The crucial step to take toward fixing it is to uncover the exact reason behind it, so here’s our list of the most probable suspects:

TAC system malfunction

A malfunctioning TAC system is the most common cause of the P1516 code. This malfunction can occur due to several reasons, such as a defective TAC motor, a damaged TAC circuit, or a faulty TAC module.

Symptoms of a TAC system malfunction include a lack of power, idle surging, and reduced fuel efficiency.

Wiring issues

Wiring problems can also cause the P1516 code, such as damaged or corroded wires. These issues can cause a short circuit or open circuit in the TAC system, leading to the code’s appearance.

ECM malfunction

An ECM malfunction can also cause the P1516 code, as the ECM is responsible for controlling the TAC system. A faulty ECM can send incorrect signals to the TAC system, leading to the code’s appearance.

Symptoms of an ECM malfunction include stalling, poor fuel efficiency, and engine misfires.

Which car models does the P1516 code affect the most?

While this code can affect a wide range of car models, some are more likely to experience this issue than others.

Here are some car models that are known to be most likely to be affected by the code P1516:

• Chevrolet Silverado: The 2003-2007 models of the Chevrolet Silverado are known to be prone to the P1516 code due to a faulty throttle actuator control (TAC) module.
• Cadillac CTS: The 2004-2007 Cadillac CTS is another model that commonly experiences the P1516 code due to a malfunctioning TAC module.
• GMC Sierra: Like the Chevrolet Silverado, the 2003-2007 GMC Sierra is also susceptible to the P1516 code due to a defective TAC module.
• Hummer H2: The 2003-2007 Hummer H2 is another model that may experience the P1516 code due to an issue with the TAC module.

How to diagnose the P1516 code

While diagnosing the code P1516 requires quite a few diagnostic tools, there are other ways of getting to know what causes the issue besides using a scanner tool. These methods include the following options:

Visual inspection

Once the code has been retrieved, the mechanic will perform a visual inspection of the vehicle’s throttle control system. This may involve checking for damaged wires or connectors, loose connections, or other visible signs of damage.

Throttle body cleaning

In some cases, the P1516 code may be triggered by a dirty or clogged throttle body. If this is suspected, the mechanic may clean the throttle body using a specialized cleaner and retest the system.

TAC module replacement

If the visual inspection and cleaning do not resolve the issue, the mechanic may need to replace the throttle actuator control (TAC) module. This component is responsible for regulating the throttle opening and may fail due to wear and tear or other issues.

Wiring repair

If damaged wiring or connectors are identified during the visual inspection, the mechanic may need to repair or replace these components to restore proper functionality.

How to fix the P1516 code

Now that you have all it takes to diagnose the issue, you are already halfway there to finally get rid of the bothersome feat. So, the next step is to fix the problem once and for all, and here are the main methods of doing so:

Throttle body cleaning

In some cases, the P1516 code may be triggered by a dirty or clogged throttle body. If this is suspected, the mechanic may clean the throttle body using a specialized cleaner. This can help to remove any debris or buildup that may be interfering with the throttle control system.

TAC module replacement

The throttle actuator control (TAC) module is responsible for regulating the throttle opening in modern vehicles. If this component fails, it can trigger the P1516 code. In these cases, the mechanic may need to replace the TAC module with a new one to restore proper functionality.

Wiring repairs

Damaged wiring or connectors can also cause the P1516 code to appear. If this is the case, the mechanic may need to repair or replace these components to restore proper communication between the different parts of the throttle control system.

Software updates

In some cases, a software update may be required to fix the P1516 code. This is particularly true if the issue is related to a programming glitch or bug in the vehicle’s computer system. In these cases, the mechanic will need to update the software with the latest version provided by the manufacturer.

How to prevent the P1516 code

Routine maintenance can help prevent the P1516 code from appearing. Here are some preventative measures:

• Regularly inspect and maintain the TAC system
• Keep the TAC system clean and free of debris
• Follow the manufacturer’s recommended maintenance schedule

In conclusion, understanding the P1516 code and diagnosing and fixing the issue promptly can help prevent further damage and ensure that your vehicle runs smoothly.

Our take

As for our final say regarding this code, it’s pretty simple – try to repair and fix the damage as soon as you spot the code to prevent having to deal with driving safety issues. Since the code can lead to serious issues with the throttle response and acceleration, it’s best to instantly fix the underlying issue so you can continue to drive safely.