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Lexus RX300 Engine Camshaft Position Sensor Guide (1999-2003)

Diagnose and fix stalling, rough idle, and starting issues on your first-generation RX300.

3 minutes to read 1999-2003 Lexus RX300
Difficulty
2/5
Est. Time
0.5 hrs
DIY Doable?
✅ Yes
Shop Labor
$37-$54
⚠️ Drivable, but... — You can drive, but the risk of the engine stalling at any time makes it a significant safety hazard that should be addressed immediately.
Key Takeaways
  • Your 1999-2003 RX300 has two camshaft position sensors; a failure can cause stalling or a no-start condition.
  • For reliability, choose Denso (the OEM supplier) or a top-tier aftermarket brand like Delphi or NGK for this critical sensor.
  • Common fault codes are P0340 for the rear sensor (Bank 1) and P0345 for the front sensor (Bank 2).
  • The front sensor (Bank 2) is an easy DIY replacement, located right below the oil cap.
Your 1999-2003 Lexus RX300 has a 3.0L V6 engine (1MZ-FE) with two camshaft position sensors. These sensors are critical for engine operation. They monitor the exact position and speed of the engine's camshafts. This information is sent to the main computer, the Engine Control Module (ECM). The ECM uses this data to precisely control when to inject fuel and when to fire the spark plugs. Proper timing is essential for good engine performance, fuel economy, and smooth running.

Is Your RX300 Stalling or Hard to Start?

A failing camshaft position sensor is a common issue on the 1999-2003 Lexus RX300 that can cause frustrating problems. Symptoms often start small, like a slightly longer crank time, but can quickly lead to the engine stalling while driving or refusing to start at all. Because these sensors are vital for engine timing, a bad signal can confuse the vehicle's computer, leading to poor performance and potential safety issues. 🎬 Watch: Understanding P0340 codes and how these sensors function. This guide will help you understand the symptoms, choose the right replacement part, and get your Lexus running smoothly again.

Choosing the Right Aftermarket Sensor: Brand Quality Tiers

When it comes to electronic sensors for your Lexus, part quality is extremely important. While many aftermarket brands are available, using a low-quality sensor can lead to incorrect signals, persistent performance problems, or a short service life, forcing you to do the job again. Forum discussions among Lexus owners consistently recommend using either OEM or a trusted OEM-equivalent brand for critical sensors.

Here’s a breakdown of the available brands for your RX300:

  • Tier 1 (OEM or Equivalent): Denso. Denso is the original equipment manufacturer for many Toyota and Lexus parts, including sensors. Choosing Denso is the closest you can get to buying the part from a Lexus dealer, ensuring the best fit, performance, and longevity. If you want to fix it right the first time, Denso is the recommended choice.
  • Tier 2 (Reputable Aftermarket): Delphi, NGK, Standard Ignition (SMP), Beck Arnley, Holstein. These are well-known aftermarket brands with a generally good reputation. They engineer their parts to meet or exceed OEM specifications. While not the original part, they are a solid alternative to the OEM and are often more readily available.
  • Tier 3 (Economy): Dorman, Global Parts, True Tech, Motorad. These brands offer a budget-friendly option. While they can be a good value, their quality can sometimes be inconsistent for sensitive electronic parts like a camshaft sensor. They may be a suitable choice for a quick fix or if budget is the primary concern, but be aware of the potential for a shorter lifespan or less precise performance compared to higher-tier brands.
Pro Tip: Your RX300 has two camshaft position sensors, one for each cylinder bank (Bank 1 and Bank 2). While you can replace just the one that has failed, it's often a good idea to replace them in pairs, especially if your vehicle has high mileage. The other original sensor may not be far from failing.

How Much Does a New Camshaft Position Sensor Cost?

The cost of replacing a camshaft position sensor depends on whether you do it yourself or take it to a shop. The part itself is relatively inexpensive, but labor costs can add up.

Part/Service Estimated Cost
New Aftermarket Sensor $30 - $74
New OEM (Lexus) Sensor $75 - $86
Shop Labor $37 - $54
Total (Shop Replacement) $203 - $220

Frequently Asked Questions

How many camshaft sensors does a 1999-2003 Lexus RX300 have?

The Lexus RX300 with the 3.0L V6 engine has two camshaft position sensors. One is for Bank 1 (the cylinder bank closer to the firewall) and the other is for Bank 2 (the cylinder bank closer to the radiator). A P0340 code typically refers to Bank 1, while a P0345 code refers to Bank 2.

Where are the camshaft position sensors located?

On the 1MZ-FE engine, the Bank 2 sensor is easily accessible on the front (radiator side) valve cover, just below the engine oil cap. The Bank 1 sensor is on the rear valve cover (firewall side) and is more difficult to access.

🎬 See this walkthrough for replacing the Bank 1 sensor.
What happens if I don't replace a bad camshaft sensor?

Ignoring a failing camshaft sensor can lead to more severe problems. You may experience worsening fuel economy, rough idling, frequent stalling, and eventually, the engine may not start at all. 🎬 Watch: How to test and replace a faulty sensor. Stalling while driving is a serious safety hazard.

Are there any recalls for the camshaft position sensor on the RX300?

No, there are no specific recalls for the camshaft position sensor on the 1999-2003 Lexus RX300. Searches of NHTSA data and forum records show recalls for other issues like airbags and lighting control units, but not for this specific part.

Camshaft position sensor bank 1 LEXUS RX300 AWD  1999
Camshaft position sensor bank 1 LEXUS RX300 AWD 1999
Lexus/Toyota P0340 Camshaft/Crankshaft Position Sensors
Lexus/Toyota P0340 Camshaft/Crankshaft Position Sensors
How To: Replace a Camshaft Position Sensor
How To: Replace a Camshaft Position Sensor
Camshaft Position Sensor P0340 Testing and Replacement HD
Camshaft Position Sensor P0340 Testing and Replacement HD

Technical Specifications

OEM Part Numbers: 90919-05026 90080-19014

The 1999-2003 Lexus RX300 is equipped with the 1MZ-FE 3.0L V6 engine, which uses two separate camshaft position sensors.

Wrenchy
Article researched & written by
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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.

Year Coverage
This article covers the Engine Camshaft Position Sensor for:
  • Lexus RX300: 19992000200120022003
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