Nissan Sentra Neutral Safety Switch Guide (2014-2019)
Having trouble starting your Sentra? The neutral safety switch could be the problem.
- A primary symptom of failure is the engine not starting in Park or Neutral.
- This is a DIY-friendly repair, but proper alignment of the new switch is critical for it to work.
- A related issue on 2016-2019 models is a faulty brake light switch (recall item), which also causes a no-start condition. Check if your brake lights work.
- The most common trouble code is P0705, indicating a transmission range sensor circuit malfunction.
Is Your Sentra Refusing to Start?
A common issue for 2014-2019 Nissan Sentra owners is a no-start condition where everything else seems fine. The lights turn on, the radio works, but the engine won't crank. 🎬 Watch this diagnostic guide for a Sentra no-start condition. While several things can cause this, a faulty neutral safety switch is a frequent culprit. This switch can fail, leaving you stranded and unable to start your car, or it can create dangerous situations like allowing the car to start in gear.
Key Symptoms of a Failing Neutral Safety Switch
- No Start in Park or Neutral: The most common symptom is the engine not starting at all. The switch fails to send the 'safe to start' signal to the computer.
- Starts in Neutral but Not Park (or Vice Versa): You might find the car only starts in one of the two correct gears. This points to a misaligned or partially failed switch.
- Starts in Any Gear: This is a serious safety hazard. If the switch shorts internally, it might allow the engine to crank while in Drive or Reverse, causing the car to lurch unexpectedly.
- Check Engine Light: A failing range sensor can trigger a Check Engine Light. The most common trouble code associated with this part is P0705, which indicates a malfunction in the transmission range sensor circuit. 🎬 See how to test and replace a faulty P0705 sensor.
- No Reverse Lights: The switch also controls the backup lights, so their failure can be another clue.
Choosing Your Aftermarket Replacement
When replacing the neutral safety switch, you have options outside of the expensive dealership part. For the 2014-2019 Sentra, aftermarket brands like Standard Ignition (SMP) and Rostra Powertrain are widely available.
- Standard Ignition (SMP): Often considered a higher-tier aftermarket brand, SMP parts are known for their robust design and extensive testing to match OE performance. They aim for a direct fit and function, making installation smoother.
- Rostra Powertrain: Rostra is another established brand in the transmission parts world. They provide a reliable, cost-effective alternative to the OEM part.
Both brands offer a quality replacement that can solve your starting issues without the high cost of an original Nissan part. The choice often comes down to budget and availability. While OEM parts are always an option, a quality aftermarket switch provides the same function and safety for a fraction of the price.
Cost of Replacing the Neutral Safety Switch
| Part Type | Estimated Cost |
|---|---|
| New OEM | $125 - $185 |
| New Aftermarket (Rostra, Standard) | $27 - $184 |
| Shop Labor | $61 - $95 |
| Total Estimated Repair (Aftermarket) | $88 - $279 |
Known Issues and Technical Bulletins (TSBs)
Nissan issued Technical Service Bulletin NTB19-072 in September 2019, announcing that the transmission range switch for 2017-2019 Sentras (and other models) is available as a separate service part. Previously, it may have been part of a larger assembly. The bulletin also provides detailed procedures for replacement and adjustment, which is critical for proper function. An improperly adjusted switch will cause the same no-start symptoms as a failed one.
Frequently Asked Questions (FAQ)
Can I replace the Sentra's neutral safety switch myself?
Yes, this is a DIY-feasible repair for someone with basic mechanical skills. The switch is located on the outside of the transmission, but you'll need to remove the battery and battery tray to access it. 🎬 Follow this step-by-step walkthrough to replace the switch yourself. The most critical part of the job is correctly aligning the new switch. If it's not aligned perfectly, the car won't start. The job typically takes about 45-75 minutes.
Is a neutral safety switch the same as a transmission range sensor?
Yes. On modern cars like the 2014-2019 Sentra, the terms are used interchangeably. The part does more than just the 'neutral safety' function; it also tells the computer the 'range' (gear) the transmission is in, so it's officially called a transmission range sensor.
My Sentra won't start, but the brake lights don't work either. Is it the neutral safety switch?
Probably not. If your brake lights are also out, the problem is more likely the brake light switch. For push-to-start models from 2016-2019, this is a very common issue covered by Nissan Safety Recall 21V-135. The car won't start because it doesn't get the signal that the brake pedal is pressed. Check for recalls on your vehicle first.
What happens if I don't replace a bad neutral safety switch?
You risk being stranded with a car that won't start. More seriously, if the switch fails in a way that allows the car to start in gear, you create a major safety risk of the vehicle moving unexpectedly. It can also lead to shifting problems and turn on the check engine light.
Helpful Videos
Technical Specifications
OEM Part Numbers: 31918-1XK0A 31918-3XX0A 31918-X420A
The neutral safety switch for the 2014-2019 Sentra is located on the exterior of the CVT transmission. It functions as a transmission range sensor, communicating the selected gear (P, R, N, D, L) to the vehicle's computer. Replacement requires removing the battery and battery tray for access and careful alignment of the new part.
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.
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