Trailblazer SS Air Suspension Sensor Part Number: How to Identify and Replace

When your Chevy Trailblazer SS’s air suspension starts acting up—riding too high, too low, or triggering a warning light—the culprit is often a faulty height sensor. Getting the exact Trailblazer SS air suspension sensor part number is critical to restoring proper ride height and system performance. This article explains the role of these sensors, lists common OEM part numbers, and provides practical guidance on finding and replacing them.

Understanding the Trailblazer SS Air Suspension System

The Trailblazer SS came equipped with a factory air suspension system that automatically adjusts ride height based on load and driving conditions. The system uses three air springs (one per corner) and a compressor, but it relies on height sensors to monitor the distance between the axle and the chassis.

Role of the Height Sensor

Each height sensor is a small arm connected to the suspension linkage. As the suspension moves, the sensor sends a voltage signal to the control module. The module then commands the compressor or release valves to add or remove air. If the sensor fails, the module gets incorrect data, causing the system to misbehave. Common symptoms include the rear end sagging, the front sitting too high, or the "Service Air Suspension" light illuminating.

Finding the Correct Part Number for Your Trailblazer SS

The Trailblazer SS uses specific air suspension sensors that are not interchangeable with standard Trailblazer models. The part number depends on the sensor’s location—left front, right front, or rear—and the model year (2006–2009).

OEM Part Numbers

While the exact number can vary, the most commonly referenced OEM part numbers for Trailblazer SS air suspension sensors are:

• Left Front Height Sensor: 15179917
• Right Front Height Sensor: 15179918
• Rear Height Sensor: 15179919

These numbers correspond to Delphi sensors, which were original equipment. Always verify with your vehicle’s VIN at a dealership or using a reputable parts catalog. Some later production models may use updated superseded numbers—confirm before ordering.

How to Locate the Sensor Number on Your Vehicle

If you already have the sensor in hand, the part number is usually stamped or labeled on the sensor body. Look for a seven-digit number starting with "151" or "258" (GM prefix). If you can’t read it, clean the sensor with a cloth. When buying a replacement, match exactly to the old sensor’s position—front left and front right sensors are often mirror images and not interchangeable.

Aftermarket Alternatives

Several aftermarket manufacturers offer sensors that match or exceed OEM specifications. Brands like Arnott, Dorman, and ACDelco (though ACDelco is OEM) produce compatible sensors. When choosing aftermarket, look for a warranty of at least one year and direct fitment claims. Avoid generic universal sensors that require wiring modifications—they can introduce reliability issues.

Step-by-Step Sensor Replacement Overview

Replacing an air suspension sensor on a Trailblazer SS is a moderate DIY job. Below is a general outline; always consult a service manual for torque specs and procedures.

Tools Needed

• Jack and jack stands
• Socket set (10mm, 13mm)
• Flathead screwdriver
• Safety glasses
• Replacement sensor (correct part number)

Safety Precautions

• Park on level ground, chock the wheels.
• Disconnect the battery negative terminal to avoid accidental air compressor activation.
• Relieve air pressure from the system: Many owners recommend cycling the ignition a few times with the engine off to vent residual pressure, but follow service manual guidance.

Replacement Steps

1. Raise the vehicle: Safely lift the corner where the sensor is located and support with jack stands.
2. Locate the sensor: It’s mounted on the frame or control arm with a plastic linkage arm.
3. Disconnect electrical connector: Press the tab and pull straight out.
4. Remove mounting bolts: Usually two 10mm bolts. Note the orientation of the sensor arm.
5. Detach the linkage: The plastic clip may be fragile—use a pick to release it.
6. Install new sensor: Attach the linkage first, then bolt the sensor in place. Tighten to spec (typically 8–10 ft-lbs).
7. Reconnect electrical connector.
8. Lower the vehicle and reconnect the battery.
9. Test the system: Start the engine and let the suspension self-level. Check for warning lights.

If the light stays on, the sensor may need calibration. Some GM vehicles require a scan tool to reset the sensor’s position. If you don’t have a scan tool, a dealership or independent shop can do it quickly.

Symptoms of a Faulty Air Suspension Sensor

Knowing these signs helps diagnose the problem before buying a new sensor:

• Uneven ride height (one corner higher or lower)
• Frequent compressor cycling (the pump runs when not needed)
• “Service Air Suspension” message on the DIC
• Sagging overnight (could also be leaking air springs)
• Harsh ride due to incorrect air pressure

If you suspect a sensor, check the wiring and connector first—corrosion or broken wires can mimic a sensor failure.

Final Recommendation: Choose the Right Part

For a reliable fix, stick with the exact OEM part number or a high-quality aftermarket sensor from a known brand. Avoid cheap, no-name sensors—they often have poor accuracy and short life. If you’re unsure which sensor is faulty, scan the system with a compatible diagnostic tool to read the fault code. Replace only the defective sensor; mixing old and new on opposite corners is fine as long as the new unit matches specifications.

By using the correct Trailblazer SS air suspension sensor part number and following a careful replacement process, you can restore your SUV’s ride quality and keep the system working for years to come.