Hummer H2 (2003-2009) Engine Camshaft Position Sensor: A Complete Guide
Fix stalling, rough idle, and starting problems by understanding and replacing this critical engine sensor in your H2.
- A failing camshaft sensor will cause stalling, hard starting, and poor performance in your H2.
- For best results, choose an OEM-equivalent brand like Delphi or a high-quality aftermarket brand like Standard Motor Products or NGK.
- The sensor location is different between the 6.0L (2003-07, rear of engine) and 6.2L (2008-09, front of engine) models; ensure you buy the correct part.
- Replacement is an easy DIY job that requires only basic tools and about 30-60 minutes.
Symptoms of a Failing Camshaft Position Sensor
When the camshaft position sensor in your Hummer H2 starts to fail, it won't leave you guessing. The engine's performance will suffer noticeably. Because the sensor provides critical data for spark timing and fuel injection, a bad signal can cause a range of problems. You will almost certainly get a Check Engine Light on your dashboard, and a code scan will likely show codes like P0340 or P0341.
🎬 Watch this video to learn more about common sensor failure symptoms.Common Failure Symptoms
- Check Engine Light: This is the most common first sign. Codes P0340, P0341, P0342, or P0343 often point to this sensor.
- Engine Stalling: The engine may stall unexpectedly, either while driving or at idle, and may not restart for some time.
- Hard Starting or No Start: The engine may crank for a long time before starting, or it may not start at all.
- Rough Idle: Your H2 may shake or vibrate more than usual when stopped in gear.
- Poor Acceleration: You'll notice a lack of power, hesitation, or stumbling when you press the gas pedal.
- Reduced Fuel Economy: With the engine running inefficiently, you'll find yourself at the gas pump more often. 🎬 See a detailed breakdown of seven signs your sensor is failing.
Choosing the Right Aftermarket Sensor
When it comes to electronic sensors, quality matters. While you can save money with an aftermarket part, choosing a reputable brand is key to avoiding doing the job twice. For the Hummer H2, the engine is a General Motors LS-based V8, which has a wide variety of available parts.
Brand Quality Tiers for Hummer H2
- OEM & OEM-Equivalent Brands (Best Quality): ACDelco is the original GM part. However, Delphi was often the original equipment manufacturer for GM, meaning a Delphi-branded sensor is frequently identical to the ACDelco part, just in a different box. These are your most reliable choices.
- High-Quality Aftermarket (Good Quality): Brands like Standard Motor Products (SMP) and NGK/NTK have a strong reputation for producing reliable sensors that meet or exceed OEM specifications. Walker Products is another well-regarded option. These brands offer a great balance of price and quality.
- Value-Oriented Brands (Use with Caution): Brands like Dorman, URO Parts, and other lower-cost options can be a gamble. While some parts may work fine, forum discussions and mechanic experiences suggest a higher failure rate for electronic sensors from these brands. They might be a temporary fix, but for a critical sensor like this, it's often worth spending a bit more for a trusted name.
Known Issues, Recalls, and Service Bulletins
Searches for official recalls on the 2003-2009 Hummer H2 through the National Highway Traffic Safety Administration (NHTSA) did not find any specific recalls for the camshaft position sensor itself. Most recalls for this vehicle range relate to other issues like the windshield wiper module or heated washer fluid system. However, some forum users have reported that issues with other components, like a failing alternator, can sometimes cause camshaft sensor error codes (like P0340) even when the sensor itself is fine. Always perform a full diagnosis before replacing parts.
Installation Details
Replacing the camshaft position sensor on the Hummer H2 is a straightforward job for a DIYer with basic tools.
- Location (2003-2007 6.0L V8): The sensor is located at the top rear of the engine block, behind the intake manifold. Access can be tight, but it is reachable.
- Location (2008-2009 6.2L V8): The sensor is located on the front of the engine, on the timing chain cover. This position is generally easier to access.
- Process: The replacement typically involves disconnecting the electrical connector, removing a single bolt (usually 10mm), and pulling the old sensor out. The new sensor is then installed, the bolt is torqued, and the connector is reattached.
| Difficulty | 1/5 (Easy) |
| DIY Time | 0.5 - 1 hour |
| Shop Labor Cost | $61 - $140 |
| New Aftermarket Part Cost | $27 - $75 |
| New OEM Part Cost | $60 - $131 |
Frequently Asked Questions
Can I still drive my H2 with a bad camshaft position sensor?
It is not recommended. While the engine may run, you risk stalling in traffic, which is a serious safety hazard. You will also experience poor performance and fuel economy, and could potentially cause damage to other components like the catalytic converter over time.
Why did my new aftermarket sensor not fix the problem?
There are a few possibilities. First, the problem could be in the wiring or connector, not the sensor itself. Second, a cheap, low-quality sensor may be dead on arrival. Third, other issues, like a failing crankshaft position sensor or even a bad alternator, can sometimes trigger a camshaft sensor code. A proper diagnosis is key.
What is the difference between the sensor for the 6.0L and 6.2L engines?
The sensors are different and located in different places. The 2003-2007 H2 with the 6.0L V8 (a Gen III LS engine) has the sensor at the rear of the block. The 2008-2009 H2 with the 6.2L V8 (a Gen IV LS engine) has it on the front timing cover. They use different part numbers and are not interchangeable. Ensure you buy the correct part for your specific year and engine.
Do I need a special tool to replace the sensor?
No special tools are typically required. A basic socket set (usually a 10mm socket) and possibly a small extension are all that's needed. For the rear-mounted sensor on the 6.0L, a flexible or universal joint for your socket wrench can make access easier.
Helpful Videos
Technical Specifications
OEM Part Numbers: 12591720 19420911 12568983 12585545 12561211
This is a 3-pin Hall Effect sensor. The location varies by engine: 2003-2007 (6.0L V8) models have the sensor at the rear of the engine block, while 2008-2009 (6.2L V8) models have it on the front timing cover.
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.
- Hummer H2: