P0747 on 2017-2024 GMC Yukon: Pressure Control Solenoid 'A' Stuck On Causes and Fixes

What's Unique About the 2017-2024 Gmc YUKON

The 2017-2024 GMC Yukon, spanning the fourth and fifth generations, utilizes 8-speed (8L90) and 10-speed 🎬 Watch: An expert explains the design flaws in these 8L90 transmissions. (10L80/10L90) automatic transmissions that are known to have issues with their control valve bodies. General Motors has issued several Technical Service Bulletins (TSBs) acknowledging that internal wear or failure within the valve body is the primary cause of code P0747. 🎬 Watch: A quick breakdown of what P0747 means for your engine. While a solenoid code on other vehicles might point to a simple solenoid swap, on these Yukons, the problem is most often the entire valve body assembly due to wear in the valve bores, not an electrical failure of the solenoid itself.

Diagnostic Flowchart

Tap your situation to follow the diagnostic path that matches what you're seeing on this vehicle.

Generation note: This issue affects both the fourth generation (2017-2020) with the 8L90 transmission and the fifth generation (2021-2024) with 8L90 and 10L80/10L90 transmissions. TSBs have been released that cover models in both generations, indicating a persistent problem with the valve bodies. GM has issued a special coverage program (N242454441) extending the warranty to 15 years or 150,000 miles for this condition on many affected vehicles.

Symptoms You May Notice

• Check Engine Light or transmission warning light is on.
• Extremely harsh or violent shifts, sometimes described as 'slamming' into gear or feeling like being rear-ended.
• Transmission is stuck in one gear (often 5th gear, a 'limp mode').
• Delayed engagement when shifting from Park to Drive or Reverse.
• Transmission slipping, where engine RPMs increase without a corresponding increase in speed.
• Reduced engine power or 'Reduced Acceleration' message on the driver information center.

Most Likely Causes

1. Failed Transmission Control Valve Body 🔴 High Probability → Shop Transmission Valve Body As documented in multiple GM TSBs (#24-NA-088, #N242454441, #25-NA-255), these vehicles are prone to internal valve body failures. The root cause is often wear of the aluminum 'Feed Limit Low' valve and its bore, which leads to pressure loss and triggers the P0747 code. Aftermarket specialists identified this wear pattern as the primary culprit even before GM's latest repair bulletins.
   How to confirm: A professional technician will use a scan tool to confirm P0747. Diagnosis is confirmed by the code's presence combined with the known TSBs. TSB #24-NA-088 provides visual guidance on fluid condition; even dark fluid without heavy clutch debris points to a valve body replacement.
   Typical fix: Initially, the fix was to replace the entire valve body assembly (e.g., ACDelco P/N 24297834). More recently, GM issued TSB #25-NA-255, which instructs dealers to repair the existing valve body by installing an updated steel Feed Limit Low valve, a stronger spring, and a new spacer plate. GM also has a special coverage program (N242454441) extending the warranty to 15 years/150,000 miles for this repair.
   Est. part cost: $400-$900
2. Low or Dirty Transmission Fluid 🟡 Medium Probability → Shop Transmission Assembly These transmissions are sealed and do not have a traditional dipstick, making fluid level checks difficult for owners. While low fluid can cause issues, heavily contaminated or burnt-smelling fluid is more often a *symptom* of internal damage (like a failing valve body or clutches) rather than the root cause.
   How to confirm: A technician must raise the vehicle on a lift to check the fluid level and condition via the check/fill plug. Dark fluid with a burnt odor or visible clutch material indicates a more severe problem than just the valve body.
   Typical fix: Perform a transmission fluid and filter change using the correct fluid (Mobil 1 LV ATF HP blue label is often recommended by owners). If the fluid is heavily contaminated, this will not solve the underlying mechanical issue. A 'flush' is not recommended.
   Est. part cost: $100-$250
3. Faulty Pressure Control Solenoid 'A' ⚪ Low Probability → Shop Transmission Valve Body While this is the component named in the code, on this platform it rarely fails on its own. Aftermarket transmission experts state it is 'extremely rare' for the solenoid itself to be the problem. The failure is almost always mechanical/hydraulic within the valve body that the solenoid controls.
   How to confirm: A technician can command the solenoid with a scan tool, but this often doesn't reveal the underlying hydraulic leak in the valve body. The solenoid may test electrically fine while the mechanical part of the system is failing.
   Typical fix: Replacement of the solenoid is almost never the correct fix. The problem will typically return until the entire valve body is replaced or repaired per the latest TSBs.
   Est. part cost: $50-$150

Rare But Worth Checking

• Wiring Harness Damage: Damage to the wiring between the TCM and the transmission can cause this code. It's worth inspecting the harness for any visible signs of chafing, melting, or corrosion, especially where it runs near hot exhaust components.
• Faulty Transmission Control Module (TCM): → Shop Transmission Assembly It is very rare for the TCM itself to fail, but it's a possibility if all other causes have been ruled out. A faulty driver circuit in the module could keep the solenoid energized.

Diagnosis Steps

1. Verify the code with a quality OBD-II scanner.
2. Check for any applicable Special Coverage programs or TSBs for the vehicle's VIN. Note Special Coverage N242454441 which extends warranty to 15yr/150k miles for this issue.
3. Check the transmission fluid level and condition. Per TSB 24-NA-088, dark fluid is acceptable, but fluid with excessive clutch material indicates a deeper failure requiring transmission inspection.
4. Inspect the transmission wiring harness and connectors for any visible damage, corrosion, or loose connections.
5. Using an advanced scan tool, a professional should monitor live transmission data, observing the commanded vs. actual pressure for solenoid 'A'.
6. If fluid and wiring are good, the diagnosis, supported by GM's own TSBs, points directly to a faulty transmission control valve body requiring replacement or repair.

Parts You'll Likely Need

• Transmission Control Valve Body (OEM #24297834 (ACDelco, verify by VIN)) — This is the most common failure point for code P0747 on these vehicles. This complete assembly was the standard fix before recent TSBs.
  Trusted brands: ACDelco (Genuine GM)
  OEM price range: $600-$900
  Aftermarket price range: $400-$700
• Valve Body Repair Kit (per TSB 25-NA-255) — As of late 2025, GM's official procedure is to repair the valve body with a kit including an updated steel Feed Limit Low Valve, a stiffer spring, and a new spacer plate. This is now the preferred dealer fix for 10-speed transmissions.
  Trusted brands: GM Genuine Parts
  OEM price range: $100-$200
• Transmission Fluid — New fluid is required when replacing the valve body. Owners and some technicians recommend Mobil 1 Synthetic LV ATF HP (blue label) over the stock fluid.
  Trusted brands: ACDelco DEXRON VI, Mobil 1 Synthetic LV ATF HP
  OEM price range: $10-$15 per quart
  Aftermarket price range: $8-$12 per quart
• Transmission Oil Pan Gasket — The old gasket should be replaced when the transmission pan is removed to access the valve body.
  Trusted brands: ACDelco, Fel-Pro
  OEM price range: $30-$50
  Aftermarket price range: $20-$40
• Sonnax Feed Limit Low Valve Kit (Aftermarket) (OEM #105740-54K) — This is a well-regarded aftermarket solution that directly addresses the root cause of the valve bore wear, similar to GM's own updated repair strategy. It is specified for Gen. 2 10-speed transmissions.
  Trusted brands: Sonnax
  Aftermarket price range: $50-$80

Related Codes That Often Appear With This One

• P0796 — This code is for 'Pressure Control Solenoid 'C' Stuck Off'. TSB #PIP5425A mentions P0747 and P0796 appearing together, which strongly indicates a widespread failure within the transmission control valve body affecting multiple hydraulic circuits.
• P0700 — This is a generic code indicating the Transmission Control Module (TCM) has requested the Check Engine Light to be turned on. It will always be present alongside a more specific transmission code like P0747.

Technical Service Bulletins (TSBs) & Recalls

• 25-NA-255: New repair procedure for P0747, instructing technicians to install an updated steel valve kit into the valve body.
• 24-NA-088: Malfunction Indicator Lamp (MIL) Illuminated, Transmission Not Shifting/Default Mode - DTC P0747 Set.
• N242454441-03: Special coverage for harsh shifting and P0747 due to pressure loss, requiring control valve body replacement.
• PIP5425A: Early investigation into DTC P0747 and P0796.

Platform-Specific Known Issues

• Bulletin #25-NA-255: The most recent GM guidance, which directs technicians to repair the existing valve body with an updated steel valve kit rather than replacing the entire assembly for P0747.
• Bulletin #N242454441-03: This is a Special Coverage program, not just a TSB. It extends the warranty on the valve body to 15 years or 150,000 miles for many affected vehicles, making the repair free of charge for eligible owners.
• Bulletin #24-NA-088: Provides diagnostic guidance, showing images of transmission fluid. It clarifies that dark fluid is often normal and acceptable for a valve body replacement, whereas fluid with significant clutch debris indicates a more severe internal failure.
• Bulletin #PIP5425A: An early bulletin for 2017 models that shows GM was investigating P0747 (along with P0796) at the beginning of this vehicle generation, indicating a long-standing issue.

Mechanic-Grade Diagnostic Values

• Pressure Control (PC) and Variable Force Solenoid (VFS) resistance — expected: 4.5–5.5 ohms. Failure: A reading outside this range indicates a failed solenoid coil.
• Transmission Fluid Temperature for Service Fast Learn — expected: 167°F (75°C) to 185°F (85°C). Failure: The GDS 2 scan tool will not allow the procedure to run if the fluid is outside this temperature range.
• Vacuum Test on Sonnax Feed Limit Low Valve Kit (105740-54K) port — expected: 18 in-Hg (minimum). Failure: A reading below 18 in-Hg indicates a leak in the valve/bore, even after the repair.

Scan Tool Commands That Help

• GDS2 (GM Global Diagnostic System 2): MCVM (Mechanical Characterization and Virtual Matching) Operations / Solenoid Valve Characterization Reprogramming — Required after replacing the transmission assembly, valve body, or Transmission Control Module (TCM). It uses the component's unique number (TUN/PUN) to download specific performance data into the TCM.
• GDS2 (GM Global Diagnostic System 2): Transmission Service Fast Learn — Required after any internal transmission repair, valve body replacement, or TCM programming. This procedure allows the TCM to learn the individual clutch apply pressures in a controlled, static test, ensuring proper shift quality.
• Professional Scan Tool: Solenoid Activation / Output Control — Used during diagnosis to command a specific solenoid on and off. A technician can listen for an audible click to confirm the solenoid is mechanically actuating, though this test will not reveal hydraulic leaks in the valve body.

Real Owner Repair Stories

• Reddit user in r/Silverado (2017 Silverado 1500 6.2L (8L90 transmission), 72,000 miles) — At a stop, the truck revved without moving, then slammed into 1st gear and would not shift up. Check engine light with code P0747.
  ❌ Tried (didn't work) The vehicle's history showed the valve body had already been replaced three times prior to the current owner.
  ✅ What actually fixed it The owner was advised by a shop that a complete transmission replacement for $11,480 was necessary, highlighting that repeated valve body replacements did not provide a permanent fix in this case.
• Reddit user in r/gmcsierra (2017 GMC Sierra 1500 5.3L (8L90 transmission), 210,000 miles) — While coming to a stop, the truck failed to disengage the gear and then clunked hard, feeling like being rear-ended. P0747 was set.
  ❌ Tried (didn't work) A transmission shop, without performing an in-depth diagnosis, immediately recommended a full transmission replacement, claiming valve bodies were on a national backorder.
  ✅ What actually fixed it The owner reported the code was cleared and had not yet returned, but was left considering options like a fluid change versus a full replacement due to the high mileage and lack of a definitive diagnosis from the shop.

"I Checked Everything" — The Actual Cause

• The most common diagnostic trap for P0747 on this platform is when a technician tests the Pressure Control Solenoid 'A' and finds it works perfectly. It may pass resistance tests (4.5-5.5 ohms) and click when activated by a scan tool. However, the code returns because the actual root cause is not an electrical failure of the solenoid, but a mechanical/hydraulic failure within the valve body. Specifically, wear in the 'Feed Limit Low' valve bore or the solenoid regulator valve bore causes a pressure leak that the solenoid cannot control, leading the TCM to incorrectly flag the solenoid as 'stuck on'.

OEM Part Supersession History

• Entire Valve Body Assembly (e.g., ACDelco 24297834) → Internal Repair Kit (Steel Feed Limit Low Valve, Spring, Spacer Plate) — GM identified the specific point of failure within the valve body (the aluminum Feed Limit Low valve bore) and created a more targeted, durable, and cost-effective repair. The new procedure repairs the existing valve body with a steel valve instead of replacing the entire aluminum assembly.
  Heads up: The new repair procedure per TSB #25-NA-255 is specified for 10-speed (10L80/10L90) transmissions. While the root cause is similar in 8-speeds, the official repair strategy may differ.

Model Year Variations Within This Range

• 2017-2020 (approx.): These years primarily use the 8-speed (8L90) transmission. Early TSBs and repairs often involved complete valve body replacement. A 'Transmission Service Fast Learn' procedure for these model years may have a different sequence than later years.
• 2021-2024 (approx.): These years primarily use the 10-speed (10L80/10L90) transmission. The latest GM TSB (#25-NA-255) specifies an internal *repair* of the valve body with an updated steel valve kit, rather than a full replacement, as the preferred fix for P0747.