2009-2010 Hummer H3T Engine Camshaft Position Sensor: A Complete Guide
Fixing hard starts, rough idling, or a P0340 code on your Hummer H3T starts here.
- Your 2009-2010 H3T has either two camshaft sensors (3.7L I5 engine) or one (5.3L V8 engine).
- Common signs of failure include a P0340 code, hard starting, rough idle, and stalling.
- For reliability, choose OEM (ACDelco) or top-tier aftermarket brands like Delphi.
- This is an easy DIY replacement that typically requires only a 10mm socket and takes less than 30 minutes.
Is Your H3T Camshaft Position Sensor Failing?
A bad camshaft position sensor can cause a range of frustrating engine problems. Because the sensor's signal is so important for engine timing, a failure can make your truck run poorly or not at all. You might notice one or more of these issues.
Common Symptoms:
- Hard Starting or No Start: The engine may crank for a long time before starting, or it might not start at all. In some cases, it may fail to restart when the engine is warm.
- Engine Stalling: The engine might suddenly shut off while driving or when coming to a stop.
- Rough Idle and Poor Performance: You may feel a rough or unstable idle, sluggish acceleration, and a general loss of engine power.
- Check Engine Light: A failing camshaft position sensor will almost always trigger the check engine light. The most common trouble code is P0340 (Camshaft Position Sensor "A" Circuit Malfunction). On 3.7L engines, "Sensor A" usually refers to the intake sensor.
A Note on Wiring
Sometimes the sensor itself is fine, but the wiring or connector is damaged, loose, or corroded. Before replacing the sensor, always inspect the wiring harness for any visible issues. A loose connection can cause the same symptoms as a failed part.
Choosing the Right Aftermarket Sensor
With many brands available, picking the right sensor can be confusing. They generally fall into three tiers of quality and price.
Tier 1: OEM and OE-Equivalent Brands
- ACDelco: As the original equipment manufacturer for GM, ACDelco parts are the benchmark for fit and performance. Choosing ACDelco is the safest bet for a hassle-free repair.
- Delphi: Delphi is another top-tier OEM supplier for many carmakers, including GM. Their sensors are built to meet or exceed factory specifications and are a highly reliable alternative to ACDelco.
Tier 2: Reputable Aftermarket Brands
- NGK, Standard Ignition (SMP), Walker Products: These are well-known brands with a long history of producing quality aftermarket parts. They offer a good balance of price and reliability and are generally considered a safe choice.
- Dorman: Dorman is known for providing cost-effective solutions that often match the original design. While they are a popular choice, forum discussions sometimes note that new-out-of-the-box failures can occur with any value-focused brand.
Tier 3: Value Brands
Many other lower-priced brands are available. While the low cost is tempting, be cautious. A poor-quality sensor can fail quickly or provide an incorrect signal, leading to continued engine problems and more time spent on diagnosis. For a critical component like this, it is often worth spending a little more for a trusted brand.
Pro Tip: Replace in Pairs?
On the 3.7L engine with two sensors, if one fails and they are both original, it's often a good idea to replace both at the same time. They have been exposed to the same heat and mileage, so the second one may not be far from failing.
How Much Does a Camshaft Sensor Replacement Cost for a 2009-2010 Hummer H3T?
Replacing this sensor is a relatively inexpensive repair. The part itself is affordable, and the labor is minimal due to easy access.
| Item | Estimated Cost |
|---|---|
| New Aftermarket Sensor | $27 - $80 |
| New OEM (ACDelco) Sensor | $55 - $115 |
| Shop Labor | $50 - $100 |
| Total Estimated Cost (DIY) | $27 - $115 |
| Total Estimated Cost (At a Shop) | $77 - $215 |
Frequently Asked Questions
How many camshaft sensors does my 2009-2010 H3T have?
It depends on your engine. The 3.7L I5 engine has two sensors (intake and exhaust). The 5.3L V8 engine has only one.
What does the P0340 code mean?
P0340 is a generic OBD-II code that means "Camshaft Position Sensor 'A' Circuit Malfunction." This indicates a problem in the circuit for the primary camshaft sensor, which could be the sensor itself, the wiring, or the connector. On the 3.7L engine, this typically points to the intake sensor.
Is an OEM sensor really better than aftermarket?
For critical timing sensors, OEM (ACDelco) or OE-equivalent (Delphi) parts are strongly recommended. While many aftermarket sensors work fine, some forum members have reported that cheap sensors can be defective out of the box or fail prematurely, causing the same problems to return.
Can I replace this sensor myself?
Yes, this is a very beginner-friendly job. The sensor is typically held in by a single 10mm bolt and is easily accessible on both the 3.7L and 5.3L engines. The entire process usually takes less than 30 minutes.
Are there any recalls for the H3T camshaft position sensor?
No. As of early 2026, there have been no recalls or technical service bulletins (TSBs) issued by GM or the NHTSA for the camshaft position sensor on the 2009-2010 Hummer H3T.
Technical Specifications
OEM Part Numbers: 12591720 12597253 12584079 213-3826 213-4223
The 3.7L I5 engine uses two sensors, often referred to as intake and exhaust sensors. The 5.3L V8 uses a single sensor in the front timing cover. The sensor is a 3-pin magnetic hall-effect sensor.
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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 H3T:
- 🛍️ Shop This Part
- Is Your H3T Camshaft Position Sensor Failing?
- Common Symptoms:
- A Note on Wiring
- Choosing the Right Aftermarket Sensor
- Tier 1: OEM and OE-Equivalent Brands
- Tier 2: Reputable Aftermarket Brands
- Tier 3: Value Brands
- Pro Tip: Replace in Pairs?
- How Much Does a Camshaft Sensor Replacement Cost for a 2009-2010 Hummer H3T?
- Frequently Asked Questions
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