Saturn Relay Crankshaft Position Sensor Guide for 2005-2007 Models
If your Saturn Relay is stalling, running rough, or won't start, a bad crankshaft sensor is a likely cause.
- Due to the high risk of the engine stalling at any time, it is not safe to drive your Relay if you suspect the crank sensor is failing.
- For maximum reliability, choose an ACDelco or Delphi brand sensor, as they are the original equipment suppliers for GM.
- The sensor is plastic and can become brittle, often breaking during removal. This can turn a difficult job into a very expensive one.
- A 'crankshaft variation relearn' procedure with a professional scan tool is required after replacement to avoid a persistent check engine light.
Symptoms of a Failing Crankshaft Sensor
When the crankshaft position sensor on your 2005-2007 Saturn Relay starts to fail, it can cause serious and sudden problems. Because the sensor's signal is essential for engine operation, a bad sensor can leave you stranded. Look for these common signs:
- Engine Stalling: The engine may shut off unexpectedly while driving, which can be very dangerous. It might happen intermittently, sometimes restarting after it cools down, and sometimes not.
- No Start or Hard Starting: Your Relay may turn over but refuse to start. This happens because the ECU doesn't get the signal it needs to fire the spark plugs and fuel injectors.
- Rough Idle and Misfires: The engine may shake, vibrate, or run poorly. An erratic sensor signal causes incorrect timing, leading to engine misfires and a rough feeling.
- Check Engine Light: This is a very common symptom. If you scan the codes, you will likely find P0335, which points directly to a problem with the crankshaft position sensor circuit.
Critical Safety Warning
The most dangerous symptom is sudden engine stalling. If your Relay stalls while driving, you will lose power steering and power brakes, increasing the risk of a crash. Driving is not recommended if you suspect the sensor is failing.
Choosing the Right Aftermarket Sensor
When replacing a critical electronic part like this, brand quality matters. Not all aftermarket sensors are created equal, and choosing a low-quality part can mean you'll be doing the job again soon.
| Brand Tier | Brands | Assessment |
|---|---|---|
| Tier 1: OEM / OEM-Equivalent | ACDelco, Delphi | These are your best and safest choices. ACDelco is GM's official parts brand, and Delphi was the Original Equipment Manufacturer for many GM electronics. Choosing one of these provides the highest confidence in fit, performance, and longevity. |
| Tier 2: Reputable Aftermarket | Standard Ignition (SMP), Hitachi, Walker Products | These brands have a long history and a generally good reputation for producing reliable electronics that meet or exceed OEM specs. They are a solid, dependable choice if an OEM-equivalent part isn't available. |
| Tier 3: Budget Options | Dorman, Holstein, True Tech, Global Parts | These brands offer a more affordable price point. However, forum and mechanic feedback suggests that quality for electronic sensors can be inconsistent. While Dorman sometimes offers innovative fixes, for a critical sensor like this, it's a budget-conscious choice that may carry more risk of premature failure. |
Mechanic's Pro-Tip: Check for Other Issues
A GM Technical Service Bulletin (TSB) notes that on some V6 engines, the metal ring (reluctor wheel) that the sensor reads can move slightly on the crankshaft. This can cause codes like P0016 or P0017 and symptoms similar to a bad sensor. If a new sensor doesn't fix the issue, this may be the underlying cause and requires more significant engine work.
Frequently Asked Questions (FAQ)
Is there a recall on the Saturn Relay crankshaft sensor?
No, there are no specific recalls from the NHTSA for the crankshaft position sensor on the 2005-2007 Saturn Relay. GM did have recalls for faulty crank sensors on other vehicles from the same era, but the Relay was not included.
Where is the crankshaft sensor located on the Saturn Relay?
The sensor is located on the engine block, typically near where the engine and transmission meet. Access is very tight. Mechanics often access it by removing the front passenger-side wheel and a rubber splash guard in the wheel well to reach it. Attempting to reach it from under the vehicle may require removing the catalytic converter.
What is a "crankshaft variation relearn" procedure?
After replacing the sensor, the engine's computer needs to be recalibrated to the new sensor's signal. This is called a crankshaft variation relearn (or CASE relearn). It requires a professional-grade scan tool and is necessary to prevent a persistent Check Engine Light and ensure the engine runs smoothly.
Can I replace this sensor myself?
This is a difficult job for a beginner. Access is tight, and the old plastic sensor can become very brittle from heat. It can easily break during removal, leaving a piece stuck in the engine block. If this happens, removing the broken piece can be a very complicated and expensive job. This repair is best left to an experienced DIYer or a professional mechanic.
Technical Specifications
OEM Part Numbers: 12574323 213-3523 213-3208
This is a magnetic sensor with a 3-pin weatherproof connector. Part numbers may vary between the 3.5L (2005-2006) and 3.9L (2006-2007) V6 engines. Always verify the part with your vehicle's specific engine before ordering.
We Have This Part in Stock
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.
- Saturn Relay: