What is the code P2101 on the Acura TL?

The P2101 code on the Acura TL points to a fault in the Throttle Actuator Control (TAC) system. In simple terms, it indicates the throttle actuator or its control circuit isn’t operating to specification.

In more detail, P2101 can be triggered by a failing TAC motor, a dirty or sticking throttle body, damaged wiring or connectors, or a software/calibration issue in the engine computer. The consequence can range from a rough idle or limited acceleration to an illuminated check engine light and, in some cases, limp mode to protect the engine.

What P2101 Means for the Acura TL

On the Acura TL, P2101 is a diagnostic trouble code (DTC) that flags a problem with the throttle actuator control system. This system governs the throttle plate’s position, which the engine computer uses to regulate air intake and engine power. When the TAC system reports a fault, the ECU may limit throttle response to prevent damage, resulting in sluggish or inconsistent acceleration.

Common Causes

Below are the most frequent culprits technicians examine when P2101 appears on an Acura TL. The list reflects situations that commonly lead to TAC-related faults.

• Faulty Throttle Actuator Control (TAC) motor or throttle body assembly


• Damaged, corroded, or loose TAC wiring harness or connector


• Carbon buildup or contamination on the throttle body or throttle plate


• PCM/ECU software calibration issue or the need for a relearn


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Addressing these issues typically requires a combination of cleaning, testing electrical connections, and in some cases replacing the throttle body or TAC motor. A software update or throttle relearn procedure may also be needed to restore proper operation.

Typical Symptoms

Owners may notice a few telltale signs when P2101 is active. The list below covers common symptoms reported by drivers.

• Check Engine Light (CEL) illuminated


• Reduced power, hesitation, or limited acceleration


• Rough idle or engine stalls in some cases


• Inconsistent throttle response or sluggish performance


• Poor fuel economy or the engine entering a safe/limp mode

If you experience these symptoms, it’s important to diagnose with a scan to confirm P2101 and check for related codes that can point to a specific cause.

Diagnosis and Fixes

Technicians typically follow a structured approach to verify P2101 and determine the appropriate repair. The steps below outline common procedures used for the Acura TL.

• Use an OBD-II scanner to confirm P2101 and review related codes, freeze-frame data, and live sensor readings


• Inspect the TAC motor and throttle body for sticking, binding, or carbon buildup; clean or replace as needed


• Check the wiring harnesses and electrical connectors to the TAC motor and throttle body for corrosion, damage, or loose pins


• Test sensor signals related to throttle position and accelerator pedal position to rule out upstream sensor faults


• Perform a throttle body relearn or ECU reflash/update if recommended by Honda/Acura service bulletins


• Replace the throttle body/TAC assembly if diagnostics indicate a failed motor or severe mechanical wear


• Clear codes and perform a road test to verify that the issue is resolved and no new codes reappear

Repair decisions depend on the specific vehicle year and condition. In many cases, addressing carbon buildup, repairing wiring, and updating software resolves P2101 without a full throttle body replacement. If replacement is needed, your mechanic will typically install a new TAC motor or throttle body assembly compatible with the TL.

Repair considerations for Acura TL models

Because P2101 involves the TAC system, proper diagnosis should distinguish TAC-related faults from sensor or communication issues. Always confirm that there are no upstream vacuum leaks or air intake problems, and ensure software calibrations are current for your model year. A professional technician with an appropriate scan tool can perform the necessary tests and re-learns safely.

Should You Drive the Car?

If a check engine light is on and P2101 is present, it is prudent to limit aggressive driving, as reduced throttle control can affect acceleration and safety. Depending on the severity and accompanying codes, the vehicle may still run in a degraded mode. If unsure, have the vehicle inspected by a qualified technician before long trips or heavy acceleration.

Summary

P2101 on the Acura TL signals a fault in the Throttle Actuator Control system, most often tied to the TAC motor, throttle body, wiring, or related software. Diagnosis typically starts with a scan, followed by checks of the TAC assembly, electrical connections, and sensor signals, with fixes ranging from cleaning and wiring repairs to software re-learns or part replacement. Resolving P2101 usually restores normal throttle response and engine performance.

How much does it cost to repair a P2101?

A P2101 repair can range from under $100 for a simple cleaning to over $1,500 for a full electronic throttle body replacement at a dealership. Most repairs fall between $400 and $700, which includes parts and labor for a full replacement of the throttle body. Other potential costs include diagnostic fees, and some vehicles may require an idle relearn or reprogramming procedure, which can add $120 or more. 
This video explains the costs associated with throttle body replacement: 59sLearnToDIY360YouTube · Feb 6, 2025
Cost breakdown

• Diagnosis: Varies depending on the shop, but can cost $100 to $200 and may be credited toward the repair. 
• Cleaning: The least expensive option, costing under $100 if the issue is just a dirty throttle plate and not a faulty actuator. 
• Throttle Body Replacement:
  • Parts: Typically range from $200 to $400 for a new actuator or throttle body, but can be $800+ for luxury or high-performance vehicles. 
  • Labor: Generally around $100 for a simple sensor replacement, but can increase to $200+ for more difficult-to-access throttle bodies. 
  • Total: The average cost is between $400 and $700, but can go up depending on the vehicle. 
• Calibration/Relearn: Some vehicles require a special procedure after replacement to reset the idle or throttle adaptation. This can cost $120 or be a quick process that doesn't add cost, depending on the vehicle and the shop. 
• Other Issues: The P2101 code could be caused by other problems, such as a vacuum leak or a faulty Mass Airflow (MAF) sensor. Addressing these issues may avoid a costly throttle body replacement altogether. 

How do I fix code P2101?

To fix a P2101 code, start by checking and cleaning the throttle body, which is a common cause. If that doesn't work, inspect the throttle body's wiring and electrical connectors for damage or loose connections. If the problem persists, you may need to replace the throttle body assembly, throttle position sensor (TPS), or the accelerator pedal position sensor. 
Initial steps

• Check for recalls and software updates: Before anything else, check if there are any technical service bulletins (TSBs) or software updates for your vehicle's make and model. 

This video explains what causes P2101 code and how to fix it: 56sOBD InsightsYouTube · Nov 10, 2023

• Clean the throttle body: 
  • Disconnect the battery and the air intake hose to access the throttle body. 
  • Use a throttle body cleaner and a soft brush or cloth to carefully clean the throttle plate and bore. 
  • Important: Do not force the throttle plate with your fingers, as this can damage the internal mechanism. 
• Check and repair wiring: 
  • Inspect the wiring harness and connectors for the throttle body and accelerator pedal for any signs of damage, corrosion, or loose connections. 
  • Repair any faulty circuits as needed. 

This video demonstrates how to clean the throttle body: 53sFlat Rate MechanicYouTube · Jun 20, 2019
Further troubleshooting

• Replace the throttle body assembly: If the throttle body itself is faulty and cleaning doesn't help, it may need to be replaced. Ensure the new one comes with a new gasket. 
• Replace the throttle position sensor (TPS): The TPS may be integrated into the throttle body, in which case you'll need to replace the entire assembly. In some cases, the TPS can be replaced separately. 
• Replace the accelerator pedal position sensor: This sensor can also cause the P2101 code, so consider replacing it if it's faulty. 
• Check for vacuum leaks: Unusable vacuum boosters or other vacuum leaks can sometimes cause this code. 
• Consider the PCM: In rare cases, the powertrain control module (PCM) can be the cause of the problem, but this should be considered a last resort after all other possibilities have been ruled out. 

This video shows how to diagnose and fix P2101 code: 1mPeter LYouTube · Sep 4, 2024
After the repair

• Perform an idle relearn procedure: After cleaning or replacing the throttle body, you may need to perform a specific relearn procedure for your vehicle. Check your owner's manual or search online for the correct procedure for your make and model. 
• Clear the codes: Clear the P2101 code using an OBD-II scanner and monitor the vehicle to see if the light comes back on. 

How to fix throttle actuator control system?

Repair Solutions

1. Dirty throttle body: Remove and thoroughly clean the throttle plate and bore.
2. Faulty TPS: Replace the throttle position sensor (may require a new throttle body if integrated)
3. Stuck throttle plate: Replace the entire throttle body assembly.

What is the code P2101 on a Acura TL?

P2101 code is usually triggered when your vehicle's powertrain control module (PCM) detects that the actual throttle position does not match the desired throttle position.