P1516 on Buick
Throttle Actuator Control (TAC) Module — Throttle Actuator Position Performance (GM)
P1516 on Buick vehicles indicates throttle actuator control (tac) module — throttle actuator position performance (gm). Au7o has documented this code across 1 Buick model — most commonly on Lucerne. P1516 is a manufacturer-specific code used mainly by General Motors vehicles (Chevrolet, GMC, Buick, Cadillac, Hummer, Saturn), where it means the electronic throttle system's actual throttle plate position doesn't match what the computer commanded. In a drive-by-wire system, the ECM reads the accelerator pedal sensors and drives a motor on the throttle body to open the throttle; if the throttle position sensors report a position that disagrees with the command for more than about a second, this code sets. Drivers typically see a "Engine Power Reduced" message with the check engine light, and the vehicle drops into limp mode with sluggish, limited acceleration; some trucks set the code with no symptoms at all. Because throttle control directly affects your ability to accelerate, it should be diagnosed promptly rather than driven around. Note that the definition differs by manufacturer: Ford uses P1516 for an Intake Manifold Runner Control (IMRC) input error on Bank 1, while Honda/Acura use a throttle actuator position definition similar to GM's. Typical repair costs on Buick range from $250 to $600, depending on the specific model and root cause.
Common Causes of P1516
- •Faulty throttle body / throttle actuator motor (the most common fix on GM trucks and SUVs)
- •Dirty or carbon-fouled throttle body causing the throttle plate to stick or move erratically
- •Poor engine ground connections (corroded GM ground points G103/G104 causing voltage drop above 0.1V)
- •Damaged wiring or corroded connectors in the TAC motor control or throttle position sensor circuits
- •Faulty throttle position sensor(s) on the throttle body
- •Failed stand-alone TAC module (separate module on 1999–2005 GM trucks)
- •ECM/PCM fault, or a needed throttle relearn after cleaning or battery disconnect
P1516 on Buick by Model
Buick Lucerne(1 issue)
- Throttle Body / Throttle Position Sensor Causing Reduced Engine Power2006-2011
A failing electronic throttle body or throttle position sensor triggers a 'Reduced Engine Power' message and limp mode, with rough or surging idle and hesitant acceleration. The condition is common enough that GM issued a special coverage adjustment extending the throttle body warranty on some 2009-2011 cars.
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View P1516 across all makes →Frequently Asked Questions
What does P1516 mean on Buick?▼
P1516 stands for "Throttle Actuator Control (TAC) Module — Throttle Actuator Position Performance (GM)." P1516 is a manufacturer-specific code used mainly by General Motors vehicles (Chevrolet, GMC, Buick, Cadillac, Hummer, Saturn), where it means the electronic throttle system's actual throttle plate position doesn't match what the computer commanded. In a drive-by-wire system, the ECM reads the accelerator pedal sensors and drives a motor on the throttle body to open the throttle; if the throttle position sensors report a position that disagrees with the command for more than about a second, this code sets. Drivers typically see a "Engine Power Reduced" message with the check engine light, and the vehicle drops into limp mode with sluggish, limited acceleration; some trucks set the code with no symptoms at all. Because throttle control directly affects your ability to accelerate, it should be diagnosed promptly rather than driven around. Note that the definition differs by manufacturer: Ford uses P1516 for an Intake Manifold Runner Control (IMRC) input error on Bank 1, while Honda/Acura use a throttle actuator position definition similar to GM's. On Buick specifically, this code is documented across 1 model.
What causes P1516 on Buick vehicles?▼
Common causes on Buick: Faulty throttle body / throttle actuator motor (the most common fix on GM trucks and SUVs), Dirty or carbon-fouled throttle body causing the throttle plate to stick or move erratically, Poor engine ground connections (corroded GM ground points G103/G104 causing voltage drop above 0.1V), Damaged wiring or corroded connectors in the TAC motor control or throttle position sensor circuits, Faulty throttle position sensor(s) on the throttle body. Specific causes vary by model and year — see the per-model sections below.
How much does it cost to fix P1516 on a Buick?▼
Repair costs on Buick range from $250 to $600, depending on the specific model and root cause.
Which Buick models have P1516 documented?▼
Au7o has documented P1516 on 1 Buick model: Lucerne.