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Engine Crankshaft Position Sensor for 2001-2005 GMC Sierra 2500 HD

Solve stalling, no-start, and rough running issues by understanding this critical engine sensor.

4 minutes to read 2001-2005 GMC Sierra 2500 HD
Difficulty
3/5
Est. Time
1.5 hrs
DIY Doable?
✅ Yes
Shop Labor
$100-$200
🚫 Do not drive — Driving is not recommended as a failing sensor can cause the engine to stall at any time, creating a serious safety risk.
Key Takeaways
  • A mandatory 'CASE relearn' procedure with a scan tool is required after replacement to avoid performance issues.
  • For reliability, choose premium brands like ACDelco or Delphi, as they were likely the original suppliers for GM.
  • Symptoms range from a simple Check Engine Light to dangerous engine stalling while driving.
  • On gas engines, the sensor is located above the starter, which must be removed for access.
The Engine Crankshaft Position Sensor is a small but vital part for your Sierra's engine. It constantly watches the position and speed of the engine's crankshaft. This information is sent to the engine control module (ECM), which is the truck's main computer. The ECM uses this signal to control when to inject fuel and when to create a spark for ignition. For both the gas (6.0L, 8.1L) and diesel (6.6L Duramax) engines in your truck, a correct signal from this sensor is necessary for the engine to start and run efficiently.

Is Your Sierra 2500 HD Stalling or Hard to Start? It Could Be the Crankshaft Sensor.

A failing crankshaft position sensor can cause a range of frustrating problems for your 2001-2005 GMC Sierra 2500 HD. Because this sensor is essential for engine timing and fuel management, a bad sensor can make your truck run poorly or even leave you stranded. Common symptoms include the engine cranking but not starting, stalling unexpectedly while driving, a rough idle, and a noticeable decrease in fuel economy. In many cases, a failing sensor will also trigger the Check Engine Light on your dashboard.

Known Issue: Recall for 8.1L Engines

General Motors issued a recall (NHTSA Campaign ID: 07V-521) for some 2001 Sierra and Silverado trucks with the 8.1L V8 engine. The recall addressed crankshaft position sensors that were prone to intermittent failure, which could cause the engine to run rough, stall, and not restart. If the sensor failed completely, the engine would stop running, increasing the risk of a crash. While the recall period is over, it highlights a known vulnerability for this specific engine.

Choosing the Right Aftermarket Crankshaft Sensor

When replacing this sensor, you have a choice between OEM and a wide variety of aftermarket brands. For a critical part like this, quality matters. Sticking to brands known for their electronics is a smart move.

  • Premium Brands (Recommended): ACDelco and Delphi are top choices. ACDelco is GM's official parts brand, and Delphi was often the original equipment manufacturer for many GM electronics of this era. Choosing one of these brands gives you the best chance of getting a part that performs just like the original.
  • Quality Aftermarket Brands: Brands like NGK/NTK, Standard Motor Products (Standard Ignition), and Hitachi are well-regarded in the aftermarket for producing reliable sensors. They are a solid alternative to the premium brands and often come at a slightly lower price point.
  • Value Brands: Brands like Dorman, Walker, and other store brands offer a budget-friendly option. While some users have success with these, forum discussions often contain mixed reviews, with some mechanics noting a higher failure rate for budget electronic parts. They can be a viable option if cost is the primary concern, but carry a higher risk of being defective out of the box or having a shorter service life.

CRITICAL STEP: The CASE Relearn Procedure

After replacing the crankshaft position sensor on a GM truck of this era (especially gas engines), you MUST perform a Crankshaft Position System Variation Learning Procedure, also known as a "CASE Relearn." This procedure requires a professional-grade scan tool. Skipping this step will likely result in a persistent Check Engine Light (DTC P1336 or P0315), rough running, and poor performance because the ECM cannot properly read the new sensor's signal. Many DIY mechanics replace the sensor but fail to do the relearn, leading them to believe the new part is faulty.

Cost to Replace the Crankshaft Position Sensor

Item Estimated Cost
New Aftermarket Part $25 - $164
Shop Labor $100 - $200
Total Estimated Cost (DIY) $25 - $164
Total Estimated Cost (Installed) $125 - $364

Frequently Asked Questions

Where is the crankshaft position sensor located on the 2001-2005 Sierra 2500 HD?

For the V8 gas engines (6.0L, 8.1L), the sensor is typically located on the passenger's side of the engine block, near the rear, just above the starter. You will likely need to remove the starter to gain access. For the 6.6L Duramax diesel engine, the sensor is usually located on the front of the engine, near the harmonic balancer.

Can I replace this sensor myself?

Yes, this is a DIY-feasible job for someone with moderate mechanical skills. The main challenge for gas engines is the tight access and the need to remove the starter. However, remember that a CASE relearn procedure with a specific scan tool is required after installation for the job to be completed correctly. Without the relearn, the truck will not run properly.

What happens if I ignore a failing crankshaft sensor?

Ignoring the symptoms can lead to more serious issues. Your truck may stall in traffic, which is a significant safety hazard. It can also lead to a no-start condition, leaving you stranded. Continued misfires and poor engine timing can also potentially damage other components, like the catalytic converter, over time.

What are the common trouble codes for a bad crankshaft sensor?

The most common trouble code is P0335 (Crankshaft Position Sensor 'A' Circuit Malfunction). You might also see P0336 (Crankshaft Position Sensor 'A' Circuit Range/Performance). After a replacement, if the CASE relearn is not performed, you will likely see code P1336 or P0315 (Crankshaft Position System Variation Not Learned).

Technical Specifications

OEM Part Numbers: 12567649 12575409 213-354 213-970 97365037

The sensor is a 3-pin magnetic reluctance sensor that generates a signal based on the passing of teeth on a reluctor wheel attached to the crankshaft. Different part numbers exist for the gas (6.0L, 8.1L) and diesel (6.6L) engines.

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 Crankshaft Position Sensor for:
  • GMC Sierra 2500 HD: 20012002200320042005
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