P0851 Buick Code - Park/Neutral Position Switch Circuit Low Voltage
Quick Answer
The P0851 Buick code indicates a problem with the park/neutral position switch circuit in the vehicle. Common causes include Faulty park/neutral position switch, Wiring issues or damaged connectors in the PNP switch circuit, Corrosion or moisture in the circuit. 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
- P0851 Buick indicates Park/Neutral Position Switch Circuit Low Voltage.
- Common causes
- Common causes include Faulty park/neutral position switch, Wiring issues or damaged connectors in the PNP switch circuit, Corrosion or moisture in the circuit.
- 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.
Fix Your Car Smarter
Try the New AutoCodes App!
Get complete OBDII diagnostics, repair solutions, and cost estimates, plus AI chat support on demand.
Code P0851 Buick Description
The P0851 Buick code indicates a problem with the park/neutral position switch circuit in the vehicle. The park/neutral position (PNP) switch, also known as the transmission range sensor, is responsible for detecting the gear position of the transmission. When the vehicle is in park or neutral, the switch sends a signal to the engine control module (ECM) to ensure that the engine can start safely. If the switch detects a low voltage signal, it means that there is an issue with the circuit, which can lead to various problems with the vehicle's performance.
Common Causes of P0851 Buick
- Faulty park/neutral position switch
- Wiring issues or damaged connectors in the PNP switch circuit
- Corrosion or moisture in the circuit
- ECM malfunction
- Transmission control module (TCM) failure
Symptoms of P0851 Buick
- Difficulty starting the engine
- Inability to shift gears
- Hesitation or jerking when shifting
- Check Engine Light illuminated on the dashboard
How to Fix P0851 Buick
- Use a diagnostic scanner to read the trouble code and verify the issue.
- Inspect the wiring and connectors in the PNP switch circuit for any damage or corrosion.
- Test the park/neutral position switch to determine if it is functioning correctly.
- Replace the faulty PNP switch if necessary.
- Clear the trouble code and test drive the vehicle to ensure the issue has been resolved.
Cost to Fix P0851 Buick
The cost of repairing a P0851 Buick code can vary depending on the specific cause of the issue and the labor rates in your area. Generally, the cost of replacing a park/neutral position switch can range from $150 to $300, including parts and labor. However, additional costs may apply if there are other underlying issues that need to be addressed. It's recommended to consult with a professional mechanic to get an accurate estimate for your specific vehicle. Keep in mind that labor rates can vary, so it's advisable to shop around for the best price.
Need more information about the P0851 Buick code?
Need more information on how to fix the P0851 Buick code? Get Access to Factory Service Manuals
Need Help with the Code?
Get the P0851 Buick code diagnosed by a professional: Find a repair shop in your area
Frequently Asked Questions about P0851 Buick Code
No Frequently Asked Questions about P0851 Buick Code found.
Discuss the causes and fixes for P0851 Buick OBDII Code
Code P0851 Buick comments
No comments found for this page.
Fix Your Car Smarter
Try the New AutoCodes App!
Get complete OBDII diagnostics, repair solutions, and cost estimates, plus AI chat support on demand.