Guide to the 1999-2006 Nissan Altima Crankshaft Position Sensor
Understand the common and frustrating stalling and starting issues with your Nissan Altima.
- Engine stalling is a major symptom and safety risk for 1999-2006 Altimas, linked to a recall on 2.5L models.
- The most common trouble code is P0335.
- Many owners and mechanics strongly recommend using OEM or high-quality aftermarket sensors to avoid repeat failures.
- It is highly recommended to replace the camshaft position sensor at the same time as the crankshaft sensor.
Is Your Altima Stalling? It Could Be the Crankshaft Sensor
Owners of the 1999-2006 Nissan Altima, especially the 2002-2006 models with the 2.5L engine, often face a common and frustrating problem: the engine stalls without warning or has trouble starting. A frequent cause for this is a failing crankshaft position sensor. This small part plays a huge role in keeping your engine running smoothly, and its failure is a well-documented issue for this generation of Altima.
Recall and Known Issues
Nissan issued a recall for some 2002, 2005, and 2006 Altima models with the 2.5L engine due to the crankshaft position sensor. The original sensors could overheat, causing the signal to cut out and the engine to stall suddenly at low speeds, which is a major safety risk. The official recall (NHTSA Campaign ID: 07V527000) involved reprogramming the engine's computer (ECM). However, many owners and mechanics find that replacing the faulty sensor is the real, long-term solution. Even if your specific car wasn't part of the recall, these sensors are a known weak point.
Common Symptoms of a Bad Sensor
When this sensor starts to fail, your car will give you clear signs. You might experience one or more of the following:
- Check Engine Light: The most obvious sign is the "Service Engine Soon" light on your dashboard. The most common trouble code stored in the computer is P0335.
- Engine Stalling: The engine may shut off unexpectedly, especially after it has warmed up or when you are driving at low speeds. This is the most dangerous symptom.
- Hard Starting: Your Altima may crank for several seconds before the engine finally starts.
- No Start: In the worst case, the engine will crank but will not start at all.
- Rough Idling and Misfires: The engine may run poorly, vibrate, or misfire because the computer can't time the spark plugs correctly.
Choosing the Right Aftermarket Part
When it comes to replacing the crankshaft sensor on a 1999-2006 Altima, the quality of the new part matters a lot. Many owners have reported that cheap, low-quality aftermarket sensors either don't work right out of the box or fail very quickly, leading them to do the job twice. For a critical part like this, it is often recommended to use a part from the original manufacturer (OEM) or a high-quality aftermarket brand. However, if you are on a budget, a standard aftermarket part can be an option, but be aware of the potential for shorter life or performance issues.
Pro Tip: Replace the Camshaft Sensor Too
Your Altima also has a camshaft position sensor that works with the crankshaft sensor. These two sensors often fail around the same time. On many 2.5L models, the crankshaft and camshaft sensors are the exact same part. To save yourself time and future headaches, it is a common and highly recommended practice to replace both sensors at the same time.
| Part/Service | Estimated Cost |
|---|---|
| New OEM Part | $81 - $133 |
| New Aftermarket Part | $31.86 - $35.34 |
| Shop Labor | $70 - $140 |
| Total Professional Replacement | $151 - $236 |
Frequently Asked Questions (FAQ)
Where is the crankshaft position sensor located?
On the 2.5L engine, the sensor is located on the back of the engine block, near the transmission. It can be difficult to see and is often reached by feel. On the 3.5L V6 engine, it is on the lower front side of the engine. You may need to remove the air intake tube or work from underneath the vehicle to gain access.
🎬 See a helpful walkthrough of the sensor's location and removal.Can I replace this sensor myself?
Yes, this is a job many DIY mechanics can handle. It requires basic tools like a 10mm socket and extensions. The main challenge is the sensor's location, which can be hard to reach. Be sure to apply a little clean engine oil to the new sensor's O-ring 🎬 Follow this step-by-step video to replace the sensor yourself. before installation.
What is the difference between a crankshaft and a camshaft sensor?
The crankshaft sensor tracks the rotation of the engine's crankshaft, while the camshaft sensor tracks the position of the camshafts (which open and close the valves). The computer uses both signals to get a complete picture of the engine's cycle. On many 2002-2006 Altimas with the 2.5L engine, the two sensors are identical parts.
Will a cheap aftermarket sensor work?
While it might work initially, many Nissan owners and mechanics report problems with non-OEM sensors for this specific part. These issues range from the part failing quickly to causing persistent starting problems. Using a higher-quality part is often recommended to ensure a lasting repair.
What does the P0335 code mean?
P0335 stands for "Crankshaft Position Sensor 'A' Circuit Malfunction." It means the engine's computer is not receiving a signal, or is receiving an incorrect signal, from the crankshaft position sensor. This is the most common code associated with a failed sensor on this vehicle.
🎬 Watch this guide on how to test for a P0335 code.Helpful Videos
Technical Specifications
OEM Part Numbers: 23731-6N21A 23731-JA00B 23731-JA00C
Typically a single-bolt Hall effect sensor with a 3-pin electrical connector. On many 2.5L models, the part is interchangeable with the camshaft position sensor.
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.
- Nissan Altima: