Engine-CodesNissan – P0850 2009 Nissan Altima Sedan

P0850 2009 Nissan Altima Sedan Code - Park/Neutral Switch

Quick Answer

The P0850 diagnostic trouble code (DTC) for a 2009 Nissan Altima Sedan refers to an issue with the Park/Neutral Switch, also known as the Transmission Range Sensor. Common causes include Worn out Park/Neutral Switch, Electrical faults in the switch, Wiring issues. Severity is High - diagnose this code as soon as possible. Driving is not recommended if the warning light is flashing, the engine runs poorly, or safety-related symptoms are present.

What it means
P0850 2009 Nissan Altima Sedan indicates Park/Neutral Switch.
Common causes
Common causes include Worn out Park/Neutral Switch, Electrical faults in the switch, Wiring issues.
Severity
High - diagnose this code as soon as possible.
Can I drive?
Driving is not recommended if the warning light is flashing, the engine runs poorly, or safety-related symptoms are present.
Table of contents Created and updated by William Orellana on Sep 17, 2024
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Code P0850 2009 Nissan Altima Sedan Description

The P0850 diagnostic trouble code (DTC) for a 2009 Nissan Altima Sedan refers to an issue with the Park/Neutral Switch, also known as the Transmission Range Sensor. This switch is responsible for indicating to the vehicle's computer system whether the transmission is in the park or neutral position. When this switch malfunctions or fails, it can lead to various issues with the vehicle's performance and safety.

OBDII Code P0850 2009 Nissan Altima Sedan - Park/Neutral Switch
P0850 2009 Nissan Altima Sedan Code - Park/Neutral Switch

Common Causes of P0850 2009 Nissan Altima Sedan

  1. Worn out Park/Neutral Switch
  2. Electrical faults in the switch
  3. Wiring issues
  4. Faulty vehicle computer system
  5. Corrosion or damage to connectors

Symptoms of P0850 2009 Nissan Altima Sedan

  1. Engine not starting or starting in gear
  2. Inability to shift out of park
  3. Cruise control not working
  4. Dashboard warning lights related to transmission
  5. Transmission shifting erratically

How to Fix P0850 2009 Nissan Altima Sedan

  1. Diagnose the issue by using a scan tool to read the DTC and inspecting the Park/Neutral Switch and related components.
  2. Replace the Park/Neutral Switch if it is found to be faulty.
  3. Check and repair any damaged wiring or connectors.
  4. Clear the DTC from the vehicle's computer system.
  5. Test drive the vehicle to ensure the issue has been resolved.

Cost to Fix P0850 2009 Nissan Altima Sedan

The typical repair costs for a Park/Neutral Switch issue can range from $150 to $300, including parts and labor. However, specific diagnosis time and labor rates at auto repair shops can vary based on factors such as location, vehicle make and model, and engine type. It's recommended to check local rates for a more accurate estimate. Most auto repair shops charge between $80 and $150 per hour, with rates potentially higher in metropolitan areas or at dealerships, and lower at independent shops.

Tech Notes for P0850 2009 Nissan Altima Sedan

For the CVT transmission the Park/Neutral Switch is located inside the shifter assembly, for the manual transmission it is located on the transmission (see picture)

When is the Code Detected?

The signal of the park/neutral position (PNP) switch is not changed in the process of engine starting and driving.

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About the author: William Orellana is a Master Mechanic and Mechanical Engineer with over 30 years of experience diagnosing and repairing vehicles. Learn more about his background.

Frequently Asked Questions about P0850 2009 Nissan Altima Sedan Code

1. What does OBDII code P0850 mean on a 2009 Nissan Altima Sedan?

P0850 indicates a problem with the Park/Neutral Switch Input Circuit, which monitors the gear position to ensure the vehicle is in park or neutral before starting.

2. What are the common symptoms of code P0850 in a 2009 Nissan Altima?

Symptoms may include the engine not starting, transmission not shifting properly, or the Check Engine Light illuminating.

3. What causes the P0850 code to appear on a 2009 Nissan Altima?

Common causes include a faulty park/neutral position switch, damaged wiring or connectors, or issues with the transmission control module (TCM).

4. How do I diagnose the P0850 code in my Nissan Altima?

Diagnose it by checking the park/neutral switch for proper operation, inspecting related wiring and connectors for damage, and using a scan tool to monitor the switch's input signal.

5. Can a bad park/neutral switch prevent my Altima from starting?

Yes, if the switch fails to send the correct signal, the vehicle may not recognize it is in park or neutral, preventing the engine from starting.

6. Is it safe to drive with the P0850 code active?

Driving with the P0850 code is not recommended, as it may lead to starting issues or improper transmission operation, which can be unsafe.

7. How much does it cost to fix the P0850 code on a 2009 Nissan Altima?

Repair costs can range from $100 to $300, depending on whether the issue is with the switch itself, wiring, or connectors.

8. Can I fix the P0850 code on my Altima myself?

If you're comfortable with basic electrical diagnostics and repairs, you may be able to fix it by replacing the park/neutral switch or repairing damaged wiring.

9. How do I reset the Check Engine Light after fixing the P0850 code?

Use an OBDII scan tool to clear the code, or disconnect the battery for a few minutes. Ensure the issue is resolved before resetting.

10. What happens if I ignore the P0850 code on my 2009 Nissan Altima?

Ignoring the code may lead to worsening starting issues, potential transmission problems, and reduced vehicle reliability over time.

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