P0851 2016 Chevrolet Silverado Code - Park/Neutral Position Switch Circuit Low Voltage
Quick Answer
The transmission manual shift shaft switch assembly, also known as the Internal Mode Switch (IMS), is a sliding contact switch attached to the manual shift shaft inside the transmission case. Common causes include Faulty Transmission Internal Mode Switch (IMS), Transmission Internal Mode Switch harness is open or shorted, Transmission Internal Mode Switch circuit poor electrical connection. 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 2016 Chevrolet Silverado indicates Park/Neutral Position Switch Circuit Low Voltage.
- Common causes
- Common causes include Faulty Transmission Internal Mode Switch (IMS), Transmission Internal Mode Switch harness is open or shorted, Transmission Internal Mode Switch circuit poor electrical connection.
- 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.
Code P0851 2016 Chevrolet Silverado Description
The state of each input is available for display on the scan tool. The five input parameters represented are Signal A, Signal B, Signal C, Signal P (Parity), and Signal N (Park/Neutral Start Signal). Park/Neutral Signal is sent from the Park/Neutral switch directly to the Engine Control Module (ECM) and is used for engine start enable. The Park/Neutral Signal circuit is not connected to the TCM internally; the circuit uses the TCM as a pass-through connector only. The Diagnostic Trouble Code (DTC) will be set when the ECM detects the Park/Neutral switch signal equals 0 V, Low, when the IMS reports a Drive range.
What are the Possible Causes of the DTC P0851 2016 Chevrolet Silverado?
- Faulty Transmission Internal Mode Switch (IMS)
- Transmission Internal Mode Switch harness is open or shorted
- Transmission Internal Mode Switch circuit poor electrical connection
- Faulty Control Solenoid Valve Assembly
- Faulty Engine Control Module (ECM)
How to Fix the DTC P0851 2016 Chevrolet Silverado?
Review the 'Possible Causes' above and visually examine the corresponding wiring harness and connectors. Check for damaged components and inspect connector pins for signs of being broken, bent, pushed out, or corroded.
What is the Cost to Diagnose the Code?
Labor: 1.0
To diagnose the P0851 2016 Chevrolet Silverado code, it typically requires 1.0 hour of labor. Rates vary by location, vehicle, and shop. Many shops charge between $80–$150 per hour; dealerships and metro areas may be higher, independents may be lower.
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Frequently Asked Questions about P0851 2016 Chevrolet Silverado Code
What does OBDII code P0851 mean on a 2016 Chevrolet Silverado?
P0851 indicates a "Park/Neutral Position Switch Circuit Low Voltage" issue, meaning the vehicle's computer has detected a low voltage signal from the park/neutral position switch circuit.
What are the symptoms of code P0851 in a 2016 Chevrolet Silverado?
Common symptoms include the inability to start the engine, improper transmission shifting, illuminated check engine light, or the vehicle starting only in certain gears.
What causes the P0851 code to appear?
Possible causes include a faulty park/neutral position switch, damaged wiring or connectors, short circuits, or issues with the transmission control module (TCM).
Can I drive my 2016 Silverado with a P0851 code?
It is not recommended to drive the vehicle with this code, as it may result in erratic shifting, starting issues, or potential safety concerns.
How do I fix the P0851 code on my Silverado?
Repairs may include replacing the park/neutral position switch, repairing or replacing damaged wiring, cleaning corroded connectors, or reprogramming the TCM if necessary.
Where is the park/neutral position switch located on a 2016 Silverado?
The park/neutral position switch is typically located on the transmission, near the gear selector linkage.
How do I diagnose the P0851 code on my Silverado?
Start by using an OBDII scanner to confirm the code, then inspect the park/neutral position switch, wiring, and connectors for damage or corrosion.
Can a dead battery cause the P0851 code?
A weak or dead battery is unlikely to directly cause this code, but low voltage in the electrical system could contribute to related issues.
Is replacing the park/neutral position switch expensive?
The cost varies, but replacing the switch typically ranges from $100 to $300, including parts and labor, depending on the location and service provider.
Will clearing the code fix the issue permanently?
Clearing the code may temporarily remove the warning light, but the underlying issue must be addressed to prevent the code from returning.
Discuss the causes and fixes for P0851 2016 Chevrolet Silverado OBDII Code
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