Hummer H2 (2003-2009) Engine Crankshaft Position Sensor: A Complete Guide
A failing crankshaft position sensor can leave your H2 dead in its tracks; this guide explains how to choose the right replacement part.
- A bad crank sensor will cause a no-start or dangerous stalling condition.
- Replacement requires removing the starter motor for access.
- A 'crankshaft variation relearn' procedure with a scan tool is mandatory after installation.
- For this critical part, choosing a top-tier aftermarket brand like Delphi or Standard Ignition is highly recommended over budget options.
Is Your Hummer H2 Stalling or Refusing to Start?
A bad crankshaft position sensor is a common reason for a Hummer H2 to crank but not start, or to stall unexpectedly while driving. Because this sensor is vital for engine timing, its failure can mimic other problems, but symptoms often appear when the engine gets hot. The sensor can become worn or damaged by heat over time, leading to intermittent signals before it fails completely. If your H2 is experiencing these issues, especially with a Check Engine Light and code P0335 or P0336, the crankshaft position sensor is a likely culprit.
Symptoms of a Failing Crankshaft Position Sensor in a Hummer H2
When this sensor starts to go bad, your H2 will give you some clear warning signs. Don't ignore them, as a complete failure will leave you stranded.
- Engine Cranks, But Won't Start: This is the most common symptom. The starter will turn the engine over, but it will never fire up and run because the computer doesn't know when to create spark and inject fuel.
- Intermittent Stalling: The engine may shut off for no reason while you're driving, especially after it has warmed up. Often, it may restart after cooling down for a few minutes.
- Check Engine Light: A failing sensor will almost always trigger the Check Engine Light. The most common trouble code associated with this part is P0335 (Crankshaft Position Sensor 'A' Circuit Malfunction).
- Rough Idling and Misfires: An erratic signal can cause the engine to run poorly, shake, or misfire because the ignition timing is incorrect.
- Reduced Engine Power: Your H2's computer may put the vehicle into a "limp mode" to prevent engine damage, resulting in sluggish acceleration.
Critical Part Warning
A failed crankshaft position sensor will prevent the engine from starting. If you are experiencing intermittent stalling, it is not safe to drive the vehicle, as it can shut off at any time without warning, creating a serious safety hazard.
Choosing the Right Aftermarket Sensor
When it comes to critical electronic sensors, quality matters. While there are many brands available, they generally fall into a few tiers for your Hummer H2.
- Top Tier (OEM Supplier/High-Quality Aftermarket): Brands like Delphi are often the original equipment manufacturer (OEM) for General Motors. Choosing Delphi is the closest you can get to buying the original part without the dealership price tag. Standard Ignition (SMP) and Hitachi also have a strong reputation for producing reliable sensors that meet or exceed OEM specifications. These are the recommended choices for reliability and peace of mind.
- Mid Tier (Reputable Aftermarket): Brands like Dorman and Spectra offer a balance of value and quality. They are widely available and are generally a reliable option for daily drivers, though some professional mechanics prefer to stick with top-tier brands for critical sensors.
- Economy Tier: Brands like Global Parts, True Tech, and other lesser-known names fall into this category. While their low price is tempting, these sensors can have a higher failure rate or shorter lifespan. For a part that can leave you stranded, saving a few dollars here is a gamble.
Pro Tip: OEM vs. Aftermarket
For a part as critical as the crankshaft position sensor on your H2's V8, spending a little extra for a top-tier brand like Delphi or Standard Ignition is a wise investment. The labor to replace this part can be more than the part itself, so you don't want to do the job twice.
Cost to Replace the Hummer H2 Crankshaft Position Sensor
| Part/Service | Estimated Cost |
|---|---|
| New Aftermarket Sensor | $27 - $97 |
| New OEM (ACDelco) Sensor | $90 - $165 |
| Shop Labor | $134 - $197 |
| Total Professional Replacement | $227 - $362 |
Installation & Known Issues
On the 2003-2009 Hummer H2, the crankshaft position sensor is located on the lower part of the engine block, right behind the starter motor. This means the starter must be removed to gain access, which makes the job more involved. The sensor is held in by a single 10mm bolt. Due to its location, the sensor can become rusted in place, so be prepared to wiggle it carefully to remove it without breaking it off in the block.
Known Issues: No specific recalls or widespread Technical Service Bulletins (TSBs) exist for the crankshaft position sensor on the 2003-2009 Hummer H2. However, failure due to heat and age after 100,000 miles is a common occurrence for this part on many GM vehicles of this era.
Frequently Asked Questions (FAQ)
Do I need to perform a "relearn" procedure after replacement?
Yes, a crankshaft position variation relearn procedure is required after replacing the sensor. This procedure calibrates the new sensor to the engine's computer. Without it, the Check Engine Light may stay on, and the engine may run rough. A professional-grade scan tool is needed to initiate the relearn process.
Where is the crankshaft position sensor located on the Hummer H2?
The sensor is located on the lower passenger side of the engine block, just above the oil pan and directly behind the starter motor. You must remove the starter to access and replace the sensor.
Can I replace the H2 crankshaft position sensor myself?
This is a moderately difficult DIY job. While the sensor itself is easy to unbolt, you must first disconnect the battery and remove the starter, which can be heavy and awkward. You will also need access to a scan tool to perform the mandatory relearn procedure. If you are not comfortable with these steps, it is best to have it done by a professional.
What is the difference between a crank sensor and a cam sensor?
They work together. The crankshaft sensor tracks the position of the crankshaft (the bottom end of the engine), while the camshaft position sensor tracks the position of the camshaft (the top end). The computer uses both signals to control timing. A failure in either sensor can cause similar symptoms.
Technical Specifications
OEM Part Numbers: 12560228 213-354
The sensor for the Hummer H2 is a 3-wire magnetic sensor that reads a 24x reluctor wheel on the crankshaft. It is secured by a single 10mm bolt and sealed with an O-ring.
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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.
- Hummer H2:
- 🛍️ Shop This Part
- Is Your Hummer H2 Stalling or Refusing to Start?
- Symptoms of a Failing Crankshaft Position Sensor in a Hummer H2
- Critical Part Warning
- Choosing the Right Aftermarket Sensor
- Pro Tip: OEM vs. Aftermarket
- Cost to Replace the Hummer H2 Crankshaft Position Sensor
- Installation & Known Issues
- Frequently Asked Questions (FAQ)
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