Throttle Position Sensor Guide for the 1987-1995 Chevrolet Blazer
Fix hesitation, rough idle, and poor shifting on your Chevy Blazer by understanding and choosing the right throttle position sensor.
- Prioritize an ACDelco or Delphi brand sensor to avoid compatibility issues common with budget brands on this vehicle.
- A bad TPS can cause symptoms that mimic a failing transmission; check the sensor before considering expensive transmission work.
- If the new sensor has slotted mounting holes, it must be adjusted with a multimeter to the correct voltage specification.
- Replacement is simple, requiring only basic hand tools, and is located on the driver's side of the throttle body.
Is Your Blazer's Throttle Position Sensor Failing?
A failing Throttle Position Sensor (TPS) on a 1987-1995 Blazer can cause a range of frustrating engine and transmission problems. Because the TPS sends incorrect information to the engine's computer, you may experience issues that seem unrelated to this small sensor. Being aware of the signs can save you from misdiagnosing other parts.
🎬 Watch: How to test your TPS with this DIY diagnostic procedure.Top 5 Failure Symptoms
- Hesitation or Bogging: When you press the gas pedal, the truck may hesitate, bog down, or accelerate poorly.
- Rough or Unstable Idle: The engine might idle too high, too low, or surge erratically when you're stopped.
- Poor Automatic Transmission Shifting: The transmission may shift hard, at the wrong times, or feel like it's slipping. This is because the transmission control module uses the TPS signal to determine shift points.
- Check Engine Light: A faulty TPS will often trigger the Check Engine Light. For these OBD-I vehicles, this is commonly associated with trouble code 21 or 22.
- Stalling: The engine may stall when you come to a stop or when you let off the gas pedal suddenly.
No Recalls or TSBs Found
Our research found no active recalls or vehicle-specific Technical Service Bulletins (TSBs) from GM or the NHTSA for the throttle position sensor on the 1987-1995 Chevrolet Blazer. Any issues are typically due to normal wear and tear.
Choosing the Right Aftermarket TPS for Your Blazer
For many parts, aftermarket brands offer a great value. However, for electronic sensors on these specific GM trucks, brand choice matters significantly. Owner forums and mechanic experiences show a strong preference for the original equipment brand to avoid immediate issues.
Brand Quality Tiers
- Tier 1: OEM & Premium Brands (Recommended)
These brands are known to meet or exceed original factory specifications and are the most reliable choice. For this particular sensor, spending a little more here can prevent a lot of headaches.
Brands: ACDelco, Delphi - Tier 2: Quality Aftermarket
These brands are well-regarded in the industry and generally produce reliable parts. They are a solid second choice if an OEM part is not available.
Brands: Standard Motor Products (SMP), NGK - Tier 3: Economy Brands
These brands offer the lowest price but have inconsistent quality reviews for this specific sensor. They carry a higher risk of being defective out of the box or failing prematurely. Use with caution if you're on a tight budget.
Brands: Dorman, Walker Products, True Tech, Replacement
Pro Tip: Check for Adjustability
Some TPS units for these Blazers have slotted mounting holes that allow for adjustment. After installation, you must use a multimeter to set the voltage at closed throttle to the correct specification (typically around 0.5V) to ensure proper idle and performance. 🎬 Watch: How to calibrate your new sensor using a multimeter. Non-adjustable sensors should theoretically work correctly upon installation, but this is where cheaper brands often fail.
Cost of a New Throttle Position Sensor
The cost to replace a TPS is relatively low, especially if you do it yourself. The part itself is affordable, and labor is minimal.
🎬 See this walkthrough on how to replace the sensor yourself.| Item | Estimated Cost |
|---|---|
| New Aftermarket Part | $24 - $75 |
| New OEM (ACDelco) Part | $60 - $100 |
| Shop Labor | $50 - $120 |
| Total Professional Replacement | $80 - $220 |
Frequently Asked Questions
Do I need to calibrate or adjust the new TPS?
Possibly. If your new sensor has elongated or slotted mounting holes, it is adjustable and must be calibrated with a multimeter to set the proper baseline voltage at idle. If the mounting holes are round and fixed, no adjustment is possible. Refer to a service manual for the exact voltage specification for your engine (usually 0.5V - 0.59V at closed throttle).
Can I just clean my old throttle position sensor?
No. The TPS is a sealed electronic sensor. The failure occurs internally as the contacts wear out, creating 'dead spots' in the voltage reading. While you should clean your throttle body assembly, cleaning the sensor itself will not fix the problem.
What happens if I ignore a bad TPS?
Ignoring a bad TPS will lead to continued poor engine performance, terrible gas mileage, and frustrating drivability issues like stalling and incorrect shifting. It puts extra stress on your transmission and can make the vehicle unreliable and unsafe to drive, especially if it stalls in traffic.
Does paying more for a TPS brand really matter for my Blazer?
For this specific part on this vehicle, yes. Owner experiences strongly indicate that budget sensors often fail to send the correct voltage signal right out of the box, causing the same problems you're trying to fix. Choosing an OEM brand like ACDelco is highly recommended to ensure compatibility and avoid having to do the job twice.
Helpful Videos
Technical Specifications
OEM Part Numbers: 17106681 17112404 17112679 17087653
3-pin connector, mounts to throttle body assembly. Operates on a 5-volt reference signal from the ECM. Adjustable versions require setting closed throttle voltage to approximately 0.5V - 0.59V.
We Have This Part in Stock
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.
- Chevrolet Blazer:
- 🎬 Helpful Videos
- 🛍️ Shop This Part
- Is Your Blazer's Throttle Position Sensor Failing?
- Top 5 Failure Symptoms
- No Recalls or TSBs Found
- Choosing the Right Aftermarket TPS for Your Blazer
- Brand Quality Tiers
- Pro Tip: Check for Adjustability
- Cost of a New Throttle Position Sensor
- Frequently Asked Questions
- 🎟️ Get 5% Off