Go-Parts
Cart 0
Your cart is empty
Add an item to see it appear here.
Wrenchy
Go-Parts Garage
Expert guides for diagnosing, troubleshooting, and replacing auto parts Expert guides for diagnosing and replacing auto parts
Browse All Articles →
🎬 Helpful Videos 🛍️ Shop This Part

Engine Crankshaft Position Sensor Guide for the 2003-2007 Saturn Ion

Everything you need to know before replacing the crankshaft position sensor on your Saturn Ion.

4 minutes to read 2003-2007 Saturn Ion
Difficulty
3/5
Est. Time
2 hrs
DIY Doable?
✅ Yes
Shop Labor
$150-$250
Used OEM Price
$10-$25
🚫 Do not drive — Driving is not recommended as the engine can stall without warning at any time, creating a serious safety hazard.
Key Takeaways
  • A primary symptom is the engine cranking but failing to start.
  • The sensor is located behind the starter motor, which must be removed for access, making the replacement moderately difficult.
  • Before replacing the sensor, confirm the major ignition switch recall has been performed on your Ion, as it causes similar stalling symptoms.
  • Choosing a high-quality brand like ACDelco or Delphi is strongly recommended to avoid repeating the labor-intensive replacement.
The engine crankshaft position sensor is a critical part of your Saturn Ion's engine management system. It constantly watches the position and rotational speed of the engine's crankshaft. 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 create a spark for ignition. Without an accurate signal from this sensor, your engine cannot run correctly, efficiently, or in some cases, at all.

Understanding Crankshaft Sensor Failure in Your Saturn Ion

The crankshaft position sensor on the 2003-2007 Saturn Ion is a common failure point that can leave you stranded. When this sensor fails, it can no longer provide the engine's computer with the vital information it needs to run. This can cause a range of problems, from a simple check engine light to your car suddenly shutting off in traffic. Understanding the symptoms and your replacement options is key to getting your Ion back on the road reliably.

Symptoms of a Failing Crankshaft Position Sensor

A bad crank sensor on a Saturn Ion will usually make itself known with very clear and often severe symptoms. Here’s what to watch for:

  • Engine Will Crank But Not Start: This is the most common and definitive symptom. The starter will turn the engine over, but it will never fire up and run.
  • 🎬 Watch: Diagnosing a crank no start condition on an Ion
  • Sudden Stalling: The engine may shut off without warning while you are driving, which can be extremely dangerous.
  • Check Engine Light: A failing sensor will almost always trigger the check engine light. The most common trouble code associated with this part is P0335 (Crankshaft Position Sensor 'A' Circuit Malfunction).
  • Rough Idling and Misfiring: Your car may shake, run unevenly, or sound like it's sputtering when stopped.
  • Poor Engine Performance: You might notice a lack of acceleration, hesitation, and overall sluggishness.

Important: Check for Ignition Switch Recalls

All 2003-2007 Saturn Ion models were part of a major safety recall for a faulty ignition switch (NHTSA Recalls 14V171000, 14063). A bad ignition switch can cause the car to stall while driving, a symptom identical to a failing crankshaft sensor. Before spending money on a new sensor, verify with a GM dealer or on the NHTSA website that this critical recall has been performed on your vehicle.

Choosing the Right Aftermarket Sensor

When it comes to a sensor this critical, brand quality matters. The labor to replace this part is the same whether you use a cheap part or a high-quality one. Choosing a reliable brand can save you from doing the job twice.

Tier 1: OEM & Premium Aftermarket

These brands are known for making the original parts for GM or have a strong reputation for quality and reliability. For a critical part like the crank sensor, these are highly recommended.

  • ACDelco: As the original equipment (OE) supplier for General Motors, this is the closest you can get to the factory part.
  • Delphi: Delphi was a major parts supplier for GM and is considered an OEM-equivalent quality brand.
  • Bosch: A top-tier German manufacturer with a global reputation for high-quality electronic components.
  • NGK / NTK: Well-known for ignition components and sensors, NTK is the sensor-focused branch of the company and is highly regarded.

Tier 2: Reputable Aftermarket

These brands offer a good balance of quality and value. They are a solid choice if a premium brand isn't in the budget.

  • Standard Motor Products (SMP): A long-standing company that produces reliable aftermarket sensors.
  • Hitachi: A respected Japanese manufacturer that makes quality electronic parts.

Tier 3: Economy Brands

These brands compete on price. While they may come with attractive warranties, some owners report a higher chance of issues. Consider these if budget is the absolute top priority.

  • Dorman: Known for making a wide range of aftermarket parts, including hard-to-find items.
  • Walker Products, Spectra Premium: These brands offer cost-effective solutions for various sensors.

Pro Tip: Given the labor involved in accessing the sensor (the starter must be removed), it is strongly recommended to choose a Tier 1 brand like ACDelco or Delphi to ensure longevity and avoid a repeat repair.

Cost of Replacing the Saturn Ion Crankshaft Sensor

The cost can be broken down into the price of the part and the cost of labor to install it.

ItemEstimated Cost
New Aftermarket Sensor$16 - $55
Shop Labor$150 - $250
Total Estimated Cost (DIY)$16 - $55
Total Estimated Cost (Shop)$166 - $305

*Labor costs are estimates and vary by location and shop rates. The job typically takes 1.5 to 2 hours.

Frequently Asked Questions (FAQ)

Where is the crankshaft sensor located on a 2003-2007 Saturn Ion?

The crankshaft position sensor is located on the back of the engine block, just above the oil filter housing. Unfortunately, it is hidden behind the starter motor, 🎬 See exactly where the sensor is located behind the starter which must be removed to access the sensor.

Can I replace this sensor myself?

Yes, this is a DIY-feasible job for someone with moderate mechanical experience. The main challenge is removing the starter motor, as the top bolt can be difficult to reach. You will need to safely raise the vehicle and work from underneath. Basic tools required include a ratchet with extensions, a 10mm socket for the sensor, and a 15mm socket for the starter bolts.

Does the new sensor need a "relearn" procedure?

For the Saturn Ion, most aftermarket sensors do not require a special programming or relearn procedure. After installation, the car's computer should automatically adapt to the new sensor. In rare cases, a "crankshaft variation relearn" might be needed if you experience a persistent check engine light, but this requires a professional scan tool. 🎬 Watch: Troubleshooting Ecotec sensor codes and performance issues Buying a quality sensor that explicitly states no programming is needed is the best approach.

Is the crankshaft sensor the same as the camshaft sensor?

No, they are different sensors. The crankshaft sensor tracks the rotation of the engine's crank, while the camshaft sensor(s) track the position of the camshafts (which control the valves). While they work together, they are separate parts with different locations and functions. Note that early Ions (2003-2004) may not have a camshaft position sensor, using the ignition control module for that signal instead.

saturn ion crank sensor location
saturn ion crank sensor location
P0336 saturn ion 2.4 ecotec
P0336 saturn ion 2.4 ecotec
2007 Saturn ion (Crank No Start)
2007 Saturn ion (Crank No Start)
Saturn Ion 2.2 Ecotec No Start No Crank FIXED
Saturn Ion 2.2 Ecotec No Start No Crank FIXED

Technical Specifications

OEM Part Numbers: 12577245 213-970 213-4704

2-pin connector, bolt-in mount, O-ring seal.

Wrenchy
Article researched & written by
Go-Parts' AI research assistant. Every article is backed by live web research, verified OEM data, and real technician knowledge — so you get accurate, up-to-date information you can trust.
Meet Wrenchy → Updated Apr 19, 2026

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 Crankshaft Position Sensor for:
  • Saturn Ion: 20032004200520062007
In this article
🎬 Helpful Videos
Jump to ▴

Email This Guide

We'll send you a link to this article so you can read it later or share it.

Added to cart · Part