GMC Envoy Crankshaft Position Sensor: A Comprehensive Guide (2002-2009)
Experiencing stalling or a no-start condition in your Envoy? Your crankshaft position sensor might be the culprit.
- A failing crankshaft sensor can cause stalling, no-starts, and a P0335 trouble code.
- For best results, use an OEM brand like ACDelco or Delphi; it's a critical sensor where quality matters.
- The sensor is located in a very tight spot on the driver's side of the engine, making replacement difficult.
- A special "CASE relearn" procedure with a professional scan tool is required after replacement.
Understanding Crankshaft Position Sensor Failure
The crankshaft position sensor is vital for your Envoy's engine to run. When it starts to fail, it sends incorrect data—or no data at all—to the engine's computer. This can cause a range of problems from annoying to leaving you stranded. Because it's so important for engine timing, a complete failure will prevent the engine from starting.
Choosing the Right Aftermarket Sensor
For a critical part like the crankshaft position sensor, the brand you choose matters. Inconsistent signals from a low-quality sensor can cause persistent performance issues that are difficult to diagnose. For the GMC Envoy, it's highly recommended to use either an OEM part or a part from an original equipment supplier.
- Tier 1 (OEM / OE Supplier): ACDelco is the genuine GM parts brand and the original equipment manufacturer for your Envoy. Delphi is also a primary OE supplier for GM and offers equivalent quality. Choosing one of these two brands is the safest bet for reliability and performance.
- Tier 2 (Reputable Aftermarket): Brands like Hitachi, NGK (NTK), and Standard Ignition (SMP) have a strong reputation for producing quality sensors that meet or exceed OEM specifications. They are a solid choice if an OEM part isn't available or if you're looking for a slight cost saving without a major quality compromise.
- Tier 3 (Value Brands): Brands like Dorman, Walker Products, and other store brands offer a budget-friendly option. While they can work, forum discussions among Envoy and Trailblazer owners often highlight a higher risk of premature failure or out-of-the-box issues with these less expensive sensors for critical applications. For a part this essential, spending a little more on a higher-tier brand is a wise investment.
Cost Overview: 2002-2009 GMC Envoy Crankshaft Sensor
| Part/Service | Estimated Cost |
|---|---|
| New Aftermarket Part | $21 - $97 |
| New OEM Part (ACDelco) | $42 - $94 |
| Shop Labor | $49 - $168 |
| Total Professional Replacement | $91 - $205+ |
Frequently Asked Questions (FAQ)
Where is the crankshaft position sensor located on the GMC Envoy?
For the 4.2L inline-6 engine, the crankshaft position sensor is located on the lower part of the engine block on the driver's side (left side), just below the starter motor. It can be difficult to see and access, often requiring you to work from underneath the vehicle or through the driver's side wheel well.
Is this a difficult part to replace myself?
The replacement is mechanically simple—it's held in by a single 10mm bolt. However, its location makes it a challenging job. Access is very tight, and you will likely be working by feel. Many owners find it frustrating due to the lack of space. While it's possible for a DIYer, patience and long-reach tools are a must.
Does the new sensor require a "relearn" procedure?
Yes, GM vehicles of this era, including the Envoy, require a "Crankshaft Position System Variation Learning Procedure" (also known as a CASE relearn) after the sensor is replaced. If this procedure is not performed, the check engine light may stay on with a code like P1336, and the engine may not run smoothly. This procedure requires a compatible professional scan tool; most basic OBD-II code readers cannot perform this function. Some owners report that disconnecting the battery for an extended period can sometimes serve a similar purpose, but the official procedure requires a scan tool.
Are there any recalls or TSBs for the Envoy crankshaft sensor?
There are no specific recalls for the crankshaft position sensor on the 2002-2009 GMC Envoy. However, GM has issued Technical Service Bulletins (TSBs) for similar vehicles regarding issues where electrical interference from other wiring in the same harness can affect the crank sensor signal, causing various drivability problems. The fix involves installing a new jumper harness with twisted pair wiring to shield the sensor's circuit.
Technical Specifications
OEM Part Numbers: 12585546 213-3520
The sensor for the 4.2L I6 engine is a single-bolt mount magnetic sensor with an integrated electrical connector and O-ring seal.
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.
- GMC Envoy: