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Guide to the 2004-2015 Cadillac CTS Throttle Position Sensor

Experiencing rough idle or a 'Reduced Engine Power' warning? Your Throttle Position Sensor may be the culprit.

4 minutes to read 2004-2015 Cadillac CTS
Difficulty
2/5
Est. Time
0.75 hrs
DIY Doable?
✅ Yes
Shop Labor
$85-$150
Used OEM Price
$50-$120 (Full Assembly)
⚠️ Drivable, but... — Driving is possible but not recommended, as the vehicle may enter a 'Reduced Engine Power' mode at any time, causing sudden loss of acceleration.
Key Takeaways
  • A 'Reduced Engine Power' message combined with code P2135 strongly indicates a failing Throttle Position Sensor.
  • You can often replace just the sensor using an aftermarket part, which is much cheaper than buying a full OEM throttle body assembly.
  • A 'relearn' procedure is recommended after installation to ensure the engine computer recognizes the new sensor's parameters.
  • GM issued a Special Coverage Adjustment for this known issue on 2008-2011 models, confirming its high failure rate.
The Throttle Position Sensor, or TPS, is a vital part of your Cadillac CTS's engine management system. It is located on the throttle body and its main job is to monitor the angle of the throttle blade, which opens and closes when you press the gas pedal. This information is sent to the engine control module (ECM) as a voltage signal. The ECM uses this data, along with information from other sensors, to precisely control the air-fuel mixture and ignition timing for smooth acceleration and efficient engine operation. In models with an automatic transmission, the TPS signal also influences gear shifting.

Is Your Cadillac CTS Throttle Position Sensor Failing?

Comparison between a clean, functioning throttle body and a failed unit with carbon buildup and worn sensor contacts.
A healthy throttle body (left) allows for smooth airflow and precise sensor readings, while carbon buildup or worn internal sensor tracks (right) lead to the 'Reduced Engine Power' mode common on the CTS.

A faulty Throttle Position Sensor (TPS) on a 2004-2015 Cadillac CTS can cause a range of noticeable engine problems. One of the most common and alarming symptoms is the "Reduced Engine Power" message appearing on your driver information center. This is a safety feature that limits engine output when the computer detects a critical sensor failure. You will also likely see the Check Engine Light.

Other common symptoms include:

  • Rough or Unstable Idle: The engine may idle erratically, surging up and down.
  • Hesitation or Stalling: When you press the gas pedal, the car might hesitate, stumble, or even stall completely, especially when coming to a stop.
  • Poor Acceleration: The car may feel sluggish and lack power when you try to accelerate.
  • Harsh Shifting: For automatic transmissions, you might experience jerky or delayed gear changes because the transmission control module relies on TPS data.

A Note on GM Special Coverage & TSBs

General Motors issued a Special Coverage Adjustment (GM Bulletin No. 14582A) for the throttle position sensor on many vehicles, including the 2008-2011 Cadillac CTS. This extended the warranty for this specific issue to 10 years or 120,000 miles. While this period has likely expired for most owners, it confirms that TPS failure is a known issue. The problem was so common that it often triggers the specific diagnostic trouble code P2135.

🎬 See a quick fix for the P2135 engine power error.

Choosing the Right Aftermarket TPS: Brand Quality

A new aftermarket throttle position sensor in its retail packaging.
High-quality aftermarket brands like ACDelco, Delphi, and Standard Motor Products offer reliable TPS replacements that often meet or exceed OEM specifications.

When replacing the TPS, you have a choice between OEM and aftermarket brands. For the Cadillac CTS, the original sensor is often integrated into the throttle body assembly and not sold separately by GM. However, many aftermarket brands offer the sensor by itself, which can save you a significant amount of money.

Tier 1: OEM & OEM-Equivalent

  • ACDelco: As GM's official parts brand, ACDelco is the closest you can get to the original part. They offer both "GM Original Equipment" and a more affordable "Gold" (formerly "Professional") line, both of which are manufactured to high standards.
  • Delphi: Delphi was an original equipment manufacturer for GM for many years. Their sensors are built to meet or exceed OE specifications and are considered a top-tier replacement option.

Tier 2: Quality Aftermarket

  • NGK/NTK: Known for their ignition components, NTK (the sensor division of NGK) produces high-quality sensors that are a reliable alternative to OEM.
  • Standard Motor Products (SMP): A long-standing and respected aftermarket manufacturer, their Standard Ignition and Intermotor brands offer dependable sensors. Some of their kits allow you to replace just the sensor instead of the whole throttle body.

Tier 3: Budget-Friendly

  • Walker Products, Motorad, Global Parts: These brands provide a more economical solution. While they can offer good value, they may not have the same long-term durability or precise calibration as the higher-tier brands. They are a viable option for budget-conscious repairs.

How Much Does a New Throttle Position Sensor Cost?

The cost can vary significantly depending on whether you replace only the sensor or the entire throttle body assembly.

Part Type Estimated Cost
New Aftermarket Sensor $36.94 - $151.82
New OEM (Full Throttle Body) $200 - $450+
Shop Labor $85 - $150

Note: Prices are estimates and can vary based on your specific CTS model, location, and the parts supplier.

Frequently Asked Questions

The throttle body assembly located on the intake manifold of a Cadillac CTS engine.
The TPS is typically mounted to the side of the throttle body assembly on the Cadillac CTS intake manifold and can often be replaced with basic hand tools.
Can I replace just the sensor, or do I need the whole throttle body?

While GM dealers typically replace the entire throttle body assembly, many aftermarket brands sell the throttle position sensor separately. This makes for a much more affordable repair. The sensor is usually held on by clips or screws and can be swapped out with basic tools.

Does a new throttle position sensor need to be calibrated or "relearned"?

Yes, a relearn procedure is often recommended after replacing the TPS or throttle body. This allows the ECM to learn the new sensor's idle and wide-open throttle positions. Simple procedures can sometimes be done without special tools, such as turning the ignition on (without starting the engine), slowly pressing the gas pedal to the floor, slowly releasing it, and then turning the ignition off. However, for best results, using a professional scan tool is the most reliable method.

🎬 Learn five effective methods to reset your throttle position sensor.
What are the common trouble codes for a bad TPS?

The most common code for this issue on a Cadillac CTS is P2135 (Throttle/Pedal Position Sensor/Switch 'A'/'B' Voltage Correlation). You might also see codes like P0121, P0122, or P0222, which also point to faults in the TPS circuit.

Is cleaning the throttle body a good first step?

Yes. Sometimes, carbon buildup around the throttle plate can cause it to stick, leading to symptoms that mimic a bad TPS. Before replacing parts, cleaning the throttle body bore and plate with a dedicated cleaner can sometimes resolve the issue.

Symptoms of a Bad Throttle Position Sensor and How See if it Has Failed
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Symptoms of a Bad Throttle Position Sensor and How See if it Has Failed
2003 Cadillac CTS Throttle Body Position Sensor Replacement
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2003 Cadillac CTS Throttle Body Position Sensor Replacement
Throttle Position Sensor (TPS) Reset – 5 Methods That Actually Work
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Throttle Position Sensor (TPS) Reset – 5 Methods That Actually Work
Gm/ Chevy Cadillac Reduced Engine Power..check engine light P2135 Quick Fix
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Gm/ Chevy Cadillac Reduced Engine Power..check engine light P2135 Quick Fix
Bad Throttle Position Sensor Symptoms And Common Problems With Faulty TPS Sensor
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Bad Throttle Position Sensor Symptoms And Common Problems With Faulty TPS Sensor

Technical Specifications

OEM Part Numbers: 19259452 213-4668

The TPS for the Cadillac CTS is typically a 6-pin sensor that mounts directly to the side of the throttle body. It functions as a potentiometer, sending a variable voltage signal to the ECM that corresponds to the throttle plate's angle.

Wrenchy
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Wrenchy
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Meet Wrenchy → Updated Jun 1, 2026

The information in this article is provided for general reference and educational purposes only. Vehicle specifications, procedures, and part compatibility can vary by production date, trim level, and region. Always consult your vehicle's factory service manual and verify part numbers before purchasing or performing repairs. Safety-critical components such as airbags, seat belts, and braking systems should be installed by a qualified professional.

Year Coverage
This article covers the Throttle Position Sensor for:
  • Cadillac CTS: 200420052006200720082009201020112012201320142015
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