AutoCodes – GMC – P251F 2018 GMC Sierra

P251F 2018 GMC Sierra Code - Power Take-Off Engine Shutdown Control Circuit High Voltage

Quick Answer

The Power Take-Off (PTO) is an upfitter integrated system that allows the user to create an auxiliary power source. Common causes include Faulty Power Take-Off (PTO) Control Module, Power Take-Off Control Module harness is open or shorted, Power Take-Off Control Module 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: P251F 2018 GMC Sierra indicates Power Take-Off Engine Shutdown Control Circuit High Voltage.
Common causes: Common causes include Faulty Power Take-Off (PTO) Control Module, Power Take-Off Control Module harness is open or shorted, Power Take-Off Control Module 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 183

How popular is this code, among other codes? Low

Repair Importance Level

Urgent (Diagnose now) (3 / 3)

Repair Difficulty Level

Advanced (Pro) (3 / 3)

What is this?

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 P251F 2018 GMC Sierra Description

The Power Take-Off (PTO) is an upfitter integrated system that allows the user to create an auxiliary power source. The PTO system specifically controls engine speed to values higher than normal base idle, PTO load relay engagement, and remote starting and shutdown of the engine. When the operator requests PTO using either the PTO switch or PTO remote, the engine RPM will increase to a default standby speed. The Engine Control Module (ECM) converts the data from the engine speed sensor to a 2 pulses/engine revolution signal. When PTO is engaged, the power take-off control module sends a serial data message to the ECM requesting engine speeds, in response to signals from the PTO switch or remote.
The Diagnostic Trouble Code (DTC) will be set when the Power Take-Off Control Module detects a fault on the PTO engine shutdown control circuit that is above or below a predetermined voltage threshold.

OBDII Code P251F 2018 GMC Sierra - Power Take-Off Engine Shutdown Control Circuit High Voltage - AutoCodes.com — P251F 2018 GMC Sierra Code - Power Take-Off Engine Shutdown Control Circuit High Voltage

What does this mean?

What are the Possible Causes of the DTC P251F 2018 GMC Sierra?

Faulty Power Take-Off (PTO) Control Module
Power Take-Off Control Module harness is open or shorted
Power Take-Off Control Module circuit poor electrical connection

How to Fix the DTC P251F 2018 GMC Sierra?

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 P251F 2018 GMC Sierra 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 P251F 2018 GMC Sierra code?

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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 P251F 2018 GMC Sierra Code

1. What does the OBDII code P251F mean on a 2018 GMC Sierra?

P251F indicates a problem with the Power Take-Off (PTO) Engine Shutdown Control Circuit, specifically that it is experiencing high voltage.

2. What are common symptoms of the P251F code in a 2018 GMC Sierra?

Common symptoms include the check engine light turning on, potential issues with PTO operation, and unexpected engine shutdowns or malfunctions.

3. What causes the P251F code to appear in a GMC Sierra?

The most common causes include faulty PTO control circuitry, a damaged PTO relay, wiring issues such as shorts or corrosion, or a malfunctioning Powertrain Control Module (PCM).

4. Can I drive my 2018 GMC Sierra with the P251F code active?

It is not recommended to drive with this code active as it may cause erratic PTO operation or unexpected engine shutdowns, potentially leading to unsafe situations.

5. How is the P251F code diagnosed in a GMC Sierra?

A technician will typically use a scan tool to verify the code, inspect the PTO circuit and wiring for damage, test the PTO relay, and check the voltage levels in the circuit.

6. What repairs are needed to fix the P251F code on a GMC Sierra?

Repairs may include replacing damaged wiring or connectors, installing a new PTO relay, or reprogramming or replacing the PCM if it is faulty.

7. How much does it cost to fix the P251F code on a 2018 GMC Sierra?

Repair costs depend on the specific issue but typically range from $100 for wiring repairs to $600 or more if the PCM needs replacement.

8. Can a faulty battery cause the P251F code in a GMC Sierra?

Yes, a weak or faulty battery can contribute to voltage issues that may trigger the P251F code.

9. How can I prevent the P251F code from recurring on my GMC Sierra?

Regularly inspect and maintain the PTO system, check for wiring damage or corrosion, and ensure the battery and electrical system are in good condition.

10. Is the P251F code specific to the 2018 GMC Sierra?

No, the P251F code can appear on other vehicles equipped with PTO systems, but the specific diagnostics and repairs may vary by model.