AutoCodes – GMC – P0756 2018 GMC Sierra

P0756 2018 GMC Sierra Code - Shift Solenoid Valve 2 Performance Stuck Off

Quick Answer

The transmission fluid pressure switch, also known as the pressure switch manifold, is a multiple switch assembly made up of 3 normally open pressure switches and 1 normally closed pressure switch. 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: P0756 2018 GMC Sierra indicates Shift Solenoid Valve 2 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 272

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
Cost to Diagnose
FAQs
Comments
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Code P0756 2018 GMC Sierra Description

The transmission fluid pressure switch, also known as the pressure switch manifold, is a multiple switch assembly made up of 3 normally open pressure switches and 1 normally closed pressure switch. Pressure switch 1 monitor shift valve 1 positioning, pressure switch 2 monitors shift valve 2 positioning and pressure switch 3 monitors shift valve 3 positionings. The normally open pressure switches 1–3 communicate the positioning to the Transmission Control Module (TCM). The position of shift valves 1–3 is controlled by 3 normally closed shift solenoid valves 1–3. When energized, the shift solenoid valves directly control the main pressure to shift valve 1, 2, or 3, which strokes the shift valve. When the shift valve is stroked, an exhaust passage is blocked and fluid pressure to the pressure switch increases. The Diagnostic Trouble Code (DTC) will be set if the shift solenoid valve 2 is commanded on and pressure switch 2 remains off for 5–12 s, depending on the transmission fluid temperature.

OBDII Code P0756 2018 GMC Sierra - Shift Solenoid Valve 2 Performance Stuck Off - AutoCodes.com — P0756 2018 GMC Sierra Code - Shift Solenoid Valve 2 Performance Stuck Off

What does this mean?

What are the Possible Causes of the DTC P0756 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
Faulty Transmission Control Module (TCM)

How to Fix the DTC P0756 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 P0756 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 P0756 2018 GMC Sierra code?

Need more information on how to fix the P0756 2018 GMC Sierra code? Get Access to Factory Service Manuals

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 P0756 2018 GMC Sierra Code

1. What does the OBDII code P0756 mean on a 2018 GMC Sierra?

P0756 indicates that the Powertrain Control Module (PCM) has detected an issue with the performance or operation of Shift Solenoid Valve 2, specifically that it is stuck in the "off" position.

2. What are the common symptoms of code P0756 on a 2018 GMC Sierra?

Symptoms may include harsh or erratic shifting, delayed shifting, slipping transmission, poor fuel economy, and the Check Engine Light being illuminated.

3. What causes the P0756 code to appear on a 2018 GMC Sierra?

Common causes include a malfunctioning shift solenoid, dirty or low transmission fluid, a clogged transmission filter, wiring issues, or internal transmission damage.

4. Can driving with the P0756 code cause further damage?

Yes, continuing to drive with this code can lead to additional transmission damage or unsafe driving conditions due to erratic shifting.

5. How do you diagnose the P0756 code on a 2018 GMC Sierra?

Diagnosis involves checking the transmission fluid level and condition, inspecting wiring and connectors, testing the shift solenoid for proper operation, and using a scan tool to monitor transmission data.

6. How do you fix the P0756 code on a 2018 GMC Sierra?

Repairs may include replacing the shift solenoid, flushing and refilling the transmission fluid, repairing damaged wiring, or addressing internal transmission issues if necessary.

7. Can low transmission fluid cause the P0756 code?

Yes, low or dirty transmission fluid can cause the shift solenoid to malfunction and trigger the P0756 code.

8. How much does it cost to repair the P0756 code on a 2018 GMC Sierra?

Repair costs vary depending on the issue but can range from $150 to $400 for solenoid replacement or up to $3,000 for more extensive transmission repairs.

9. Is the P0756 code specific to the 2018 GMC Sierra?

No, P0756 is a generic OBDII code that can apply to many vehicles, but the diagnostic and repair process may vary depending on the make and model.

10. How can I prevent the P0756 code from occurring again?

Regular maintenance, such as checking and replacing transmission fluid, addressing transmission issues promptly, and ensuring wiring connections are secure, can help prevent this code from reoccurring.