1990-1997 Infiniti Q45 Engine Camshaft Position Sensor: A Complete Guide
Solve stalling, no-start, and rough running issues in your first-generation Q45 by understanding this critical sensor.
- A failing camshaft sensor is a very common cause of stalling, no-starts, and rough running on the 1990-1997 Q45.
- The most common trouble code associated with this failure is P0340.
- For this specific part, enthusiasts strongly recommend using a more reliable (though more expensive) OEM sensor to avoid repeat failures.
- Before replacing the sensor, always inspect the wiring connector for damage or corrosion, as it can cause the same symptoms.
Is Your Q45 Stalling or Refusing to Start? It Could Be the Camshaft Sensor.
If you're dealing with an engine that suddenly dies, struggles to start, or runs rough, a faulty camshaft position sensor is a common culprit on the first-generation Infiniti Q45. This sensor provides vital information for engine timing, and when its signal becomes weak or is lost, the engine's computer can't properly manage the fuel and spark systems. This can lead to a range of frustrating and potentially dangerous symptoms.
Symptoms of a Failing Camshaft Position Sensor
- Engine Stalling: The engine may shut off unexpectedly while driving or when idling at a stoplight. This is a serious safety concern.
- Hard Start or No-Start: You may have to crank the engine for an extended period, or it may not start at all.
- Rough Idle: The engine may shake, sputter, or vibrate when the car is stationary.
- Poor Acceleration: The car may feel sluggish and lack power when you press the gas pedal.
- Check Engine Light: A failing sensor will almost always trigger the check engine light and store a diagnostic trouble code, most commonly P0340.
Known Issues: Wiring and Connectors
Before you replace the sensor, carefully inspect the wiring harness and connector that plugs into it. Over time, the plastic can become brittle and the metal pins can corrode, causing a poor connection that mimics the symptoms of a failed sensor. Sometimes, simply cleaning the connector or repairing a damaged wire is all that's needed.
Choosing the Right Aftermarket Part: OEM vs. Aftermarket
When it comes to critical electronic sensors on Japanese vehicles from this era, the choice between Original Equipment Manufacturer (OEM) and aftermarket parts is important. For the 1990-1997 Q45, many enthusiasts and experienced mechanics strongly recommend using an OEM sensor from Nissan/Infiniti. While they cost more, they are often considered more reliable and less likely to fail prematurely.
Aftermarket brands offer a more budget-friendly option. Here’s an honest look at the available brands:
- Standard Ignition (SMP): Generally a well-regarded aftermarket manufacturer. They emphasize quality control and testing in their marketing materials. However, some user reviews for specific camshaft sensors have reported early failures, leading them to purchase an OEM part instead.
- Walker Products: Another major aftermarket supplier that promotes its parts as meeting or exceeding OE specifications. They are a known alternative for many sensors and fuel system components.
Pro Tip: Given the critical role of this sensor and the potential for being stranded, spending extra for an OEM part is often considered a worthwhile investment to avoid doing the job twice.
Cost to Replace the Camshaft Position Sensor
The cost can vary depending on the part you choose and whether you perform the replacement yourself. The job is accessible for a DIY mechanic with basic tools.
| Part/Service | Estimated Cost |
|---|---|
| New Aftermarket Part (Standard, Walker) | $300.51 - $456.88 |
| New OEM Part | $249 - $281 |
| Shop Labor | $96 - $141 |
| Total Professional Replacement (OEM Part) | $345 - $422 |
Frequently Asked Questions
Where is the camshaft position sensor located on a 1990-1997 Q45?
On the VH45DE V8 engine, the camshaft position sensor is located on the front of the engine, typically on one of the timing chain covers, reading the position of the camshaft. It is held in by a single 10mm bolt.
Can I drive my Q45 with a bad camshaft position sensor?
It is strongly recommended not to. The biggest risk is that the engine can stall at any time, including at high speeds or in traffic, which is a major safety hazard. If you suspect the sensor is failing, you should get the vehicle repaired as soon as possible.
Was there a recall for the camshaft position sensor on the Q45?
There was a recall (NHTSA ID: 03V-455) for camshaft position sensors on some Nissan and Infiniti vehicles due to faulty solder joints that could cause stalling. However, this recall primarily affected later models, such as the 2002 Q45. While it doesn't officially cover the 1990-1997 range, it shows a history of potential issues with these sensors from the manufacturer.
Is replacing the camshaft position sensor a difficult DIY job?
No, for most people with basic tools, this is a relatively easy job. It involves removing an electrical connector and a single bolt, then pulling the old sensor out and installing the new one. Always make sure to apply a little clean engine oil to the new sensor's O-ring to ensure a good seal.
Technical Specifications
OEM Part Numbers: 23731-6P000 23731-4M506 23731-4M505
The sensor for the VH45DE engine is typically a Hall-effect type sensor that reads the camshaft's rotation from the front of the engine. It is secured by a single 10mm bolt.
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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.
- INFINITI Q45:
- 🛍️ Shop This Part
- Is Your Q45 Stalling or Refusing to Start? It Could Be the Camshaft Sensor.
- Symptoms of a Failing Camshaft Position Sensor
- Known Issues: Wiring and Connectors
- Choosing the Right Aftermarket Part: OEM vs. Aftermarket
- Cost to Replace the Camshaft Position Sensor
- Frequently Asked Questions
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