AutoCodes – GMC – P0751 2018 GMC Sierra

P0751 2018 GMC Sierra Code - Shift Solenoid Valve 1 Performance Stuck Off

Quick Answer

The shift solenoid 1 is part of the control solenoid valve assembly which has no serviceable parts. Common causes include Low transmission fluid level, Dirty transmission fluid, Faulty Control Solenoid Valve Assembly. 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: P0751 2018 GMC Sierra indicates Shift Solenoid Valve 1 Performance Stuck Off.
Common causes: Common causes include Low transmission fluid level, Dirty transmission fluid, Faulty Control Solenoid Valve Assembly.
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 259

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 Mar 25, 2024

Description
Possible Causes
How To Fix
Tech Notes
Cost to Diagnose
FAQs
Comments
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Code P0751 2018 GMC Sierra Description

The shift solenoid 1 is part of the control solenoid valve assembly which has no serviceable parts. The control solenoid valve assembly is attached to the lower control valve body. The solenoid operates by the Transmission Control Module opening or closing the ground circuit. With the solenoid circuit grounded (solenoid on), the internal plunger and metering ball block the exhaust fluid creating signal fluid pressure. The signal fluid acts against the clutch select valve 2 to overcome the valve spring force moving it to the apply position, allowing the shift. The shift solenoid 1 is commanded ON in Park, Reverse, Neutral, and Drive 1 Engine Braking, and commanded OFF in Drive 1–6 gear ranges. The Diagnostic Trouble Code (DTC) will be set when the gear slip is greater than 400 RPM for 2 s.

OBDII Code P0751 2018 GMC Sierra - Shift Solenoid Valve 1 Performance Stuck Off - AutoCodes.com — P0751 2018 GMC Sierra Code - Shift Solenoid Valve 1 Performance Stuck Off

What does this mean?

What are the Possible Causes of the DTC P0751 2018 GMC Sierra?

Low transmission fluid level
Dirty transmission fluid
Faulty Control Solenoid Valve Assembly
Control Solenoid Valve Assembly harness or connectors
Control Solenoid Valve Assembly circuit is open or shorted

How to Fix the DTC P0751 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 does this mean?

Code Tech Notes

When a transmission solenoid is stuck off, in most cases the problem is not the electrical part of the solenoid; the problem is foreign material obstructing the mechanical function of the solenoid or the flow of the fluid through the transmission valve body. If the transmission fluid is very dirty, it is recommended to change the transmission fluid and if possible, remove the transmission pan for further diagnosis. Excessive debris or metal particles on the transmission pan could be an indication that there is a transmission mechanical failure, and that the transmission will need to be rebuilt or replaced.

What is the Cost to Diagnose the Code?

Labor: 1.0

To diagnose the P0751 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.

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Need Help with the 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 P0751 2018 GMC Sierra Code

1. What does OBDII code P0751 for a 2018 GMC Sierra mean?

The P0751 code indicates a performance issue with Shift Solenoid Valve 1, specifically that it is stuck in the off position.

2. What are the common symptoms associated with OBDII code P0751 in a 2018 GMC Sierra?

Common symptoms of P0751 may include harsh shifting, transmission slipping, decreased fuel efficiency, and the transmission getting stuck in a single gear.

3. What are the possible causes of OBDII code P0751 in a 2018 GMC Sierra?

Potential causes of P0751 include a faulty shift solenoid, low transmission fluid level, dirty transmission fluid, electrical issues, or a malfunctioning transmission control module.

4. How serious is OBDII code P0751 in a 2018 GMC Sierra?

While the vehicle may still be operable with this code, it is important to address it promptly to prevent further damage to the transmission and ensure safe driving conditions.

5. Can I continue driving my 2018 GMC Sierra with OBDII code P0751?

It is not recommended to continue driving with the P0751 code present as it can lead to more severe transmission problems over time. It is best to have the issue diagnosed and repaired as soon as possible.

6. How can I diagnose OBDII code P0751 in a 2018 GMC Sierra?

Diagnosing P0751 typically involves conducting a thorough inspection of the transmission system, checking the shift solenoid, inspecting the transmission fluid, and using a scan tool to gather data from the vehicle's computer.

7. What are some repair tips for fixing OBDII code P0751 in a 2018 GMC Sierra?

Repair tips may include replacing the faulty shift solenoid, performing a transmission fluid flush and filter change, checking and repairing any damaged wiring, or resetting the transmission control module.

8. Will resetting the OBDII code P0751 in a 2018 GMC Sierra make it go away permanently?

Simply resetting the code may temporarily clear the warning light, but if the underlying issue causing the P0751 code is not addressed, it is likely to reappear.

9. How much does it cost to repair OBDII code P0751 in a 2018 GMC Sierra?

The cost of repairing P0751 can vary depending on the root cause of the issue, the extent of the repairs needed, and labor costs. It is advisable to consult with a qualified mechanic for an accurate estimate.

10. Can I fix OBDII code P0751 in a 2018 GMC Sierra myself?

While some DIY enthusiasts may be able to address simpler causes like low transmission fluid or damaged wiring, diagnosing and repairing P0751 often requires specialized tools and expertise, so it is recommended to seek professional help.