Engine Intake Manifold Temperature Sensor for 1995-1999 GMC C1500 Suburban
Is your '95-'99 Suburban running rough or getting poor gas mileage? A bad intake air temperature sensor could be the problem.
- A bad IAT sensor on a '95-'99 Suburban commonly causes a Check Engine Light (P0113, P0112), poor gas mileage, and rough running.
- The sensor is located in the air intake tube and is a very simple part to replace yourself in under 15 minutes with basic tools.
- There are no major recalls or TSBs for this specific part; failures are typically due to age.
- Quality aftermarket brands like Standard Ignition offer a reliable and cost-effective alternative to more expensive OEM parts.
Is Your Suburban Running Rough? It Could Be The Intake Air Temp Sensor
If your 1995-1999 GMC C1500 Suburban is experiencing poor fuel economy, a rough idle, or has a Check Engine Light on, a faulty Engine Intake Manifold Temperature Sensor is a common and inexpensive part to check. This sensor, often called the IAT, tells your engine's computer how hot or cold the air is. When it fails, the computer gets bad information and can't run the engine efficiently. This can lead to a variety of noticeable problems.
Symptoms of a Failing IAT Sensor
A bad IAT sensor can make your truck act up in several ways. Because the computer relies on its signal for so many adjustments, a failure can mimic other problems. Here are the most common signs:
- Check Engine Light: This is often the first sign. The computer will store a trouble code like P0112 (circuit low) or P0113 (circuit high).
- Poor Fuel Economy: If the sensor wrongly tells the computer the engine is cold, the computer will enrich the fuel mixture, wasting gas.
- Rough Idle: An incorrect air-fuel mixture can cause the engine to idle unevenly or feel shaky when you're stopped.
- Hard Starting: Especially when cold, if the sensor is sending a wrong signal, the computer might not provide the right fuel mixture for a quick start.
- Hesitation or Sluggish Acceleration: Your Suburban might feel weak or slow to respond when you press the gas pedal because the computer is confused about the air temperature.
Pro Tip: Where is the IAT sensor located?
On the 1995-1999 GMC C1500 Suburban, the Intake Air Temperature sensor is typically located in the air intake duct, between the air filter box and the throttle body. It's a small, two-wire sensor that is either pushed into a rubber grommet or threaded into the intake tube. It is generally easy to access with basic hand tools.
Choosing the Right Aftermarket Sensor
For a vehicle like the '95-'99 Suburban, you don't need to pay dealership prices for a quality sensor. Reputable aftermarket brands offer excellent reliability and performance that often meets or exceeds original equipment standards for a fraction of the cost. When choosing a replacement, consider the brand's reputation for electronic components.
- Standard Ignition (SMP): A well-regarded brand in the aftermarket, Standard Ignition produces a wide range of automotive electronics. Their sensors are known for being direct-fit replacements that undergo extensive testing to ensure reliability and performance. Customer reviews are generally positive, citing good fit and function.
- True Tech: While reviews for the specific "True Tech" parts brand are scarce, the name is more commonly associated with automotive repair shops that are generally well-reviewed for honesty and fair pricing. When considering a lesser-known parts brand, it's important to check the warranty and return policy. For a simple and low-cost sensor like the IAT, it can be a budget-friendly option.
For this specific part, both OEM and quality aftermarket sensors are simple thermistors. The key difference is often just the price. A well-known aftermarket brand like Standard Ignition is a safe and cost-effective choice that provides reliable performance.
Cost of Replacing an Intake Air Temperature Sensor
| Part/Service | Estimated Cost |
|---|---|
| New OEM Sensor | $45 - $70 |
| New Aftermarket Sensor | $19 - $31 |
| Shop Labor | $50 - $100 |
Known Issues, Recalls, and TSBs
As of early 2026, there are no specific recalls or widespread Technical Service Bulletins (TSBs) from GMC or the NHTSA directly related to the Intake Air Temperature sensor for the 1995-1999 GMC C1500 Suburban. Most issues are related to normal wear and tear of the electronic component over time.
Frequently Asked Questions
Can I replace the IAT sensor myself?
Yes, this is a very easy job for a DIYer. The sensor is located in the air intake tube and is usually held in by a grommet or threads. You'll typically only need basic hand tools like a screwdriver or a small wrench. The entire job can often be completed in under 15 minutes.
What happens if I ignore a bad IAT sensor?
While you can usually still drive the vehicle, ignoring a bad sensor is not recommended. You will experience poor fuel economy, which costs you money. Over time, an incorrect air-fuel ratio can lead to other problems, like fouled spark plugs or damage to the catalytic converter.
My Check Engine Light is on. How do I know it's the IAT sensor?
The best way to know for sure is to use an OBD-II scanner to read the diagnostic trouble codes (DTCs). Codes P0112 (Intake Air Temperature Sensor Circuit Low Input) and P0113 (Intake Air Temperature Sensor Circuit High Input) point directly to a problem with the IAT sensor or its circuit.
Should I clean the old sensor or just replace it?
Sometimes the sensor can be covered in oil or dirt, which can affect its reading. You can try cleaning it with a dedicated mass air flow sensor cleaner. However, given the low cost of a new aftermarket sensor, replacement is often the most reliable and time-effective solution.
Technical Specifications
OEM Part Numbers: 25036751 25037334
Two-terminal thermistor, typically with a threaded or push-in design, located in the air intake path.
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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.
- GMC C1500 Suburban: