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Engine Camshaft Position Sensor for 2001-2006 GMC Sierra 3500

Solve stalling, rough idle, and no-start problems by understanding the camshaft position sensor in your Sierra 3500.

4 minutes to read 2001-2006 GMC Sierra 3500
Difficulty
2/5
Est. Time
0.75 hrs
DIY Doable?
✅ Yes
Shop Labor
$138-$202
⚠️ Drivable, but... — Driving is not recommended as the engine may stall unexpectedly, which is a significant safety risk.
Key Takeaways
  • A failing camshaft sensor is a common cause of stalling, rough idle, and no-start conditions on the 2001-2006 Sierra 3500.
  • Diagnostic codes P0340 and P0341 are strong indicators of a camshaft position sensor circuit problem.
  • For reliability, choose high-quality aftermarket brands like ACDelco, Delphi, or Standard Motor Products for this critical sensor.
  • The sensor location differs between gas (rear of engine) and diesel (front of engine) models, affecting replacement difficulty.
The engine camshaft position sensor is a critical part of your truck's engine management system. It tells the engine's computer (PCM) the exact position and speed of the camshaft. This information is vital for controlling when the fuel injectors spray fuel and when the spark plugs fire. On your 2001-2006 Sierra 3500, whether you have a gas (6.0L, 8.1L) or diesel (6.6L) engine, this sensor ensures the engine runs efficiently and makes good power. Without a correct signal, the engine timing can be thrown off, leading to a host of performance issues.

Is Your Truck Stalling or Hard to Start? It Could Be the Camshaft Sensor.

If your GMC Sierra 3500 is suddenly stalling, having trouble starting, or running rough, a bad camshaft position sensor is a likely culprit. This small sensor plays a huge role in how your engine runs. When it starts to fail, it can leave you stranded. Understanding the symptoms and knowing how to choose the right replacement part can save you time and money.

Don't Ignore a Failing Sensor

While the truck might still run for a while with a failing sensor, it's not recommended to drive it. Sudden stalling, especially in traffic, is a serious safety hazard. Continuing to drive can also lead to poor fuel economy and potentially cause further engine problems.

Common Failure Symptoms

A failing camshaft position sensor usually gives you a few warning signs. The most obvious is the Check Engine Light. If you scan the codes, you'll likely see P0340 or P0341, which point directly to a problem with the sensor's circuit or performance.

  • Hard Starting or No Start: The engine cranks but takes a long time to start, or won't start at all.
  • Engine Stalling: The engine may shut off unexpectedly while idling at a stoplight or even while driving.
  • Rough Idle: The engine shakes or vibrates more than usual when the truck is stopped.
  • Poor Acceleration: The truck may feel sluggish and lack power when you press the gas pedal.
  • Reduced Fuel Economy: Incorrect engine timing leads to inefficient combustion, making your truck burn more fuel.

Choosing the Right Aftermarket Sensor

When it comes to critical engine sensors, quality matters. While you can save money with aftermarket parts, it's important to choose a reputable brand to avoid replacing the part again in a few months. For this specific sensor on a Sierra 3500, sticking with higher-quality brands is strongly recommended by mechanics.

Brand Quality Tiers

Tier 1: OEM & Premium Aftermarket

These brands are either the original equipment manufacturer (OEM) or are known for matching OEM quality and reliability. They are the safest bet for a long-lasting repair.

  • ACDelco: As GM's own parts brand, this is often the same part your truck was built with. It's the benchmark for quality.
  • Delphi: Delphi was once part of GM and is a major OEM supplier. Their sensors are widely considered to be as good as the original parts.

Tier 2: Reputable Aftermarket

These brands have a solid reputation for producing quality components that are a good balance between price and performance.

  • Standard Motor Products (Standard Ignition): A long-standing, respected name in aftermarket engine management parts.
  • NGK/NTK: Known for their high-quality ignition parts and sensors.
  • Hitachi: An OEM supplier for many vehicle manufacturers, known for reliable electronics.
  • Walker Products: A well-known brand in the fuel and engine management space.

Tier 3: Economy Brands

These brands offer the lowest prices but can be a gamble in terms of quality and longevity. While they might work, they have a higher chance of premature failure, especially for a critical sensor like this.

  • Brands like Dorman, Spectra, and other value-focused options fall into this category. While Dorman offers a huge catalog, forum discussions often point to inconsistent quality for their sensors compared to ACDelco or Delphi.

Pro Tip: Check the Connector

Sometimes the sensor itself is fine, but the electrical connector or wiring is damaged, corroded, or loose. This can cause the same symptoms as a failed sensor. Always inspect the connector and wiring harness when replacing the sensor.

Replacement Cost

The cost to replace the camshaft position sensor can vary depending on whether you do it yourself or take it to a shop. The part itself is relatively inexpensive.

Item Estimated Cost
New Aftermarket Part $18 - $119
New OEM Part $45 - $100
Shop Labor $138 - $202
Total Professional Replacement $183 - $274

Frequently Asked Questions

Where is the camshaft position sensor located on a 2001-2006 Sierra 3500?

The location depends on your engine. On the 6.0L and 8.1L V8 gas engines, the sensor is typically located at the rear of the engine block, near the top, behind the intake manifold. On the 6.6L Duramax diesel engine, the location can vary by year (LB7 vs. LLY), but it is generally found on the front of the engine, often near the water pump or on the timing cover. Always consult a repair manual for your specific engine to confirm the location.

Can I replace this sensor myself?

Yes, this is a DIY-feasible job for many home mechanics. It usually involves removing a single bolt and disconnecting an electrical connector. The main challenge is access, especially on the gas engines where the sensor is at the back of the engine. The difficulty is low, and it typically takes under an hour.

Is the camshaft sensor the same as the crankshaft sensor?

No, they are two different sensors, though they work together. The camshaft sensor tracks the position of the camshaft (top of the engine), while the crankshaft position sensor tracks the position of the crankshaft (bottom of the engine). A failure in either sensor can cause similar symptoms, so it's important to diagnose the problem correctly using the specific trouble codes.

Are there any recalls for this part?

No specific recalls were found for the camshaft position sensor itself on the 2001-2006 GMC Sierra 3500. However, Technical Service Bulletins (TSBs) may exist for related issues. For example, TSBs for newer models sometimes point to issues with camshaft actuator solenoids that can cause similar codes, but no direct TSBs for sensor failure on this generation were prominently found.

Technical Specifications

OEM Part Numbers: 12568983 12585545 12572656

Typically a 3-pin hall-effect sensor that reads the camshaft's rotational speed and position. It is held in place by a single bolt and sealed with an O-ring.

Wrenchy
Article researched & written by
Go-Parts' AI research assistant. Every article is backed by live web research, verified OEM data, and real technician knowledge — so you get accurate, up-to-date information you can trust.
Meet Wrenchy → Updated Apr 19, 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 Engine Camshaft Position Sensor for:
  • GMC Sierra 3500: 200120022003200420052006
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