AutoCodes – Chevrolet – P257E 2018 Chevrolet Silverado

P257E 2018 Chevrolet Silverado Code - Engine Hood Switch Circuit Low Voltage

Quick Answer

The Engine Control Module (ECM) applies 5 V to the hood ajar signal circuit and monitors the voltage to determine the position of the hood. Common causes include Faulty Hood Ajar Switch, Hood Ajar Switch harness is open or shorted, Hood Ajar 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: P257E 2018 Chevrolet Silverado indicates Engine Hood Switch Circuit Low Voltage.
Common causes: Common causes include Faulty Hood Ajar Switch, Hood Ajar Switch harness is open or shorted, Hood Ajar 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.

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Code Popularity 927

How popular is this code, among other codes? Low

Repair Importance Level

Urgent (Diagnose now) (3 / 3)

Repair Difficulty Level

Advanced (Pro) (3 / 3)

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Table of contents Created and updated by William Orellana on Sep 21, 2022

Description
Possible Causes
How To Fix
Cost to Diagnose
FAQs
Comments
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Code P257E 2018 Chevrolet Silverado Description

The Engine Control Module (ECM) applies 5 V to the hood ajar signal circuit and monitors the voltage to determine the position of the hood. The hood ajar switch contains a multiplexed resistor. This resistor will vary the voltage seen by the Engine Control Module by pulling down the applied voltage based on the position of the switch. The Diagnostic Trouble Code (DTC) will be set when the Engine Control Module detects a short to ground in the hood ajar signal input to the Engine Control Module.

OBDII Code P257E 2018 Chevrolet Silverado - Engine Hood Switch Circuit Low Voltage - AutoCodes.com — P257E 2018 Chevrolet Silverado Code - Engine Hood Switch Circuit Low Voltage

What does this mean?

What are the Possible Causes of the DTC P257E 2018 Chevrolet Silverado?

Faulty Hood Ajar Switch
Hood Ajar Switch harness is open or shorted
Hood Ajar Switch circuit poor electrical connection
Faulty Engine Control Module (ECM)

How to Fix the DTC P257E 2018 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 P257E 2018 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.

Need more information about the P257E 2018 Chevrolet Silverado code?

Need more information on how to fix the P257E 2018 Chevrolet Silverado code? Get Access to Factory Service Manuals

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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 P257E 2018 Chevrolet Silverado Code

What does the OBDII code P257E mean on a 2018 Chevrolet Silverado?

P257E indicates that the Engine Control Module (ECM) has detected a low voltage issue in the engine hood switch circuit.

What are the symptoms of the P257E code?

Common symptoms include the check engine light turning on, possible warning messages about the hood being open, and issues with systems like the remote start.

What causes the P257E code to appear?

This code is typically triggered by a faulty hood switch, damaged wiring, corroded connectors, or a low battery voltage issue.

Can a bad battery cause the P257E code?

Yes, a weak or failing battery can cause voltage irregularities that may trigger this code.

How do I fix the P257E code on my Silverado?

Inspect and replace a faulty hood switch, repair damaged wiring or connectors, and ensure the battery is in good condition.

Can I still drive with the P257E code?

Yes, but features like remote start may not work properly, and itâ€™s best to address the issue promptly to avoid further complications.

How do I test the hood switch circuit?

Use a multimeter to check for proper voltage and continuity in the hood switch and its wiring. Replace the switch if it's not functioning correctly.

Does the P257E code clear itself after a repair?

The code may clear after a successful repair and a few drive cycles, but you can use an OBDII scanner to reset it immediately.

Is the P257E code covered under warranty for a 2018 Silverado?

It depends on the vehicle's warranty status and coverage. Check with your Chevrolet dealer for details.

Can a software update fix the P257E code?

In rare cases, a software update from the dealer might address the issue if itâ€™s related to the ECM calibration, but physical issues like a faulty switch usually require repair.