P1516Manufacturer-specific code

P1516 Code: Throttle Actuator Position Performance (GM)

On General Motors vehicles (Chevrolet, GMC, Buick, Cadillac), the P1516 code means the throttle actuator position performance is off. The engine barely accelerates and the vehicle goes into reduced power. Other brands may define this number differently.

Severity
High
Can I keep driving?
Yes, but with caution
Estimated cost
$0 to $450
Difficulty
Medium
System
Idle and Speed Control
Applies to
Depends on the manufacturer

Common in: Chevrolet

Updated Reviewed by Renzo Chacca

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What the P1516 code means

P1516 is a manufacturer-specific code: the 1 in the second position means each automaker defines what it means, not the generic SAE standard. The most widespread definition is the one used by General Motors (Chevrolet, GMC, Buick, Cadillac). If your vehicle is another brand, confirm the code text with a scan tool that supports that manufacturer.

ManufacturerMeaning of P1516
General Motors (Chevrolet, GMC, Buick, Cadillac)Throttle actuator position performance

On a GM electronic throttle, a module compares the commanded position with the actual one using the position sensors.

The computer sets the P1516 code when the actual position does not follow the commanded one: the throttle is dirty, the motor is worn or there is a connection fault. The vehicle goes into reduced power.

Before you start repairs, confirm the make, model, year and engine. With manufacturer codes, the same number can change even between engines from the same brand.

P1516 code symptoms

  • Reduced power message.
  • The engine barely accelerates.
  • Check engine light on.

Likely causes of the P1516 code

  1. Dirty throttle body. Confirm it with the tests in the diagnosis section.
  2. Worn throttle motor. Confirm it with the tests in the diagnosis section.
  3. Throttle connector. Check the lock tab, the pins and any sign of moisture or corrosion.
  4. Low voltage. Confirm it with the tests in the diagnosis section.

How to diagnose the P1516 code step by step

  1. Clean the throttle body and check that the plate moves freely.
  2. Inspect the connector for corrosion and loose pins.
  3. Compare commanded and actual position on the scan tool.

How to fix the P1516 code

  • Clean or replace the throttle body.
  • Perform the throttle relearn.

Technical reference data

  • The two position signals must add up to a constant value.
  • P1xxx codes are manufacturer-specific: confirm the definition with a scan tool that supports your brand.
  • Reference values: check the manufacturer data for your vehicle.

Brand-specific notes

On these vehicles a simple cleaning and relearn fixes a good share of cases, so it is worth trying before you buy a throttle body.

P1516 on GM

Very common on the early 2000s Chevrolet Trailblazer, Silverado, Impala and Malibu.

If your vehicle is another brand, check the table above for the meaning its manufacturer gives this code and confirm it with a compatible scan tool.

Frequently asked questions about P1516

What does the P1516 code mean on a GM?
It means the throttle actuator position performance is off. The engine barely accelerates and the vehicle goes into reduced power.
Does P1516 mean the same thing on every brand?
No. It is a manufacturer-specific code, so on other brands it may not exist or may mean something different. Confirm it with a scan tool that supports your make.
Can I drive with a P1516 code?
With caution. A P1516 code puts the vehicle in reduced power, so acceleration is limited and merging or passing becomes risky. Get it checked soon.
How much does it cost to fix P1516?
Roughly $0 to $450 on a GM. A cleaning and relearn can cost almost nothing, while a new throttle body costs the most.
Will a P1516 code clear itself?
Only if the cause was temporary, such as a brief voltage drop. If the throttle is dirty or worn, the code returns until it is cleaned or replaced.
What is the most common cause of P1516?
A dirty throttle body or a worn throttle motor. The connector and low system voltage are the next things to check.

Related codes

Questions about the P1516 code

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