P0747 on 2020-2025 Hyundai Palisade: Causes for Pressure Control Solenoid 'A' Stuck On

What's Unique About the 2020-2025 Hyundai Palisade

The Palisade uses Hyundai's A8LF1/A8LF2 8-speed automatic transmission. While there are no specific recalls or Technical Service Bulletins (TSBs) for the P0747 code on the Palisade, Hyundai has issued TSB 22-AT-005H for a range of other transmission solenoid electrical codes (P074800, P074100, etc.) on this exact vehicle and transmission. That bulletin recommends replacing the specific solenoid and the internal valve body wiring harness, suggesting this is a known repair strategy for solenoid-related faults. Owner forums also contain reports of transmission shifting issues on the 2020 Palisade that were resolved with transmission replacement under warranty, suggesting that the 8-speed automatic can be sensitive to internal faults. 🎬 Watch: Common Palisade problems and defects Additionally, TSB 20-AT-020H provides the procedure for transferring oil pressure characteristic data to the new TCU using GDS Mobile after a transmission or TCU replacement to reduce learning time and improve shift quality.

Symptoms You May Notice

• Harsh, jerky, or banging gear shifts
• Transmission getting stuck in one gear
• Vehicle entering 'limp mode' with reduced power
• Engine stalling when coming to a stop
• Delayed engagement when shifting from Park to Drive or Reverse
• Check Engine Light is on

Most Likely Causes

1. Faulty Pressure Control Solenoid 'A' 🔴 High Probability → Shop Transmission Valve Body Based on TSBs for related codes on this platform (22-AT-005H), individual solenoid failure is a recognized issue. The solenoid can fail mechanically (stuck plunger) or electrically (internal short).
   How to confirm: A technician will use a scan tool to monitor solenoid commands vs. actual pressure readings. The solenoid's resistance can also be tested with a multimeter after accessing it; a typical resistance value for Hyundai solenoids is around 5-7 Ω. 🎬 Watch: How to diagnose and test Hyundai 8-speed solenoids
   Typical fix: Replace the faulty solenoid. This requires removing the transmission pan and valve body.
   Est. part cost: $80-$150
2. Damaged Internal Transmission Wiring Harness 🟡 Medium Probability → Shop Transmission Assembly Hyundai's TSB for related solenoid codes (22-AT-005H) explicitly recommends replacing the valve body harness along with the solenoid, indicating it's a known failure point that can become brittle or develop shorts.
   How to confirm: Visual inspection of the harness for brittle wires, chafing, or damaged connectors once the transmission pan is removed.
   Typical fix: Replace the internal wiring harness, usually done at the same time as the solenoid replacement.
   Est. part cost: $100-$200
3. Low or Contaminated Transmission Fluid 🟡 Medium Probability → Shop Transmission Assembly
   How to confirm: Check the transmission fluid level and condition. The Palisade does not have a traditional dipstick, so this must be done by a mechanic via the fill and level plugs. 🎬 See: How to change Palisade transmission fluid Fluid that is dark, burnt, or contains debris indicates a problem and can cause solenoids to stick.
   Typical fix: Perform a transmission fluid drain and fill. If the fluid is heavily contaminated, a full transmission replacement may be necessary due to other internal damage.
   Est. part cost: $150-$300 for fluid service
4. Failing Transmission Valve Body ⚪ Low Probability → Shop Transmission Valve Body While less common than a solenoid failure, TSBs for other manufacturers (like GM's 10-speed) show that worn bores or sticking regulator valves within the valve body can cause a P0747 code even when the solenoid itself tests good.
   How to confirm: This is typically diagnosed after replacing the solenoid and harness doesn't fix the issue. Worn bores or passages within the valve body can cause pressure loss or sticking valves, mimicking a solenoid fault.
   Typical fix: Replace the entire transmission valve body assembly.
   Est. part cost: $800-$1500

Rare But Worth Checking

• Faulty Transmission Control Module (TCM): → Shop Transmission Assembly This is rare. A faulty TCM typically causes multiple, erratic codes, not just a single solenoid code. It should only be considered after all other possibilities have been exhausted.
• Failing Transmission Pump: → Shop Transmission Assembly A failing high-pressure transmission pump can cause erratic pressure readings that might be misinterpreted as a solenoid issue, though this is less common than the solenoid itself failing.

Diagnosis Steps

1. Verify the code with a professional OBD-II scanner.
2. Check for any other related transmission codes.
3. Check the transmission fluid level and condition. This must be done by a professional as there is no dipstick.
4. Inspect the external transmission wiring and connectors for any visible damage.
5. Use an advanced scan tool like Hyundai GDS to monitor the TCM's commands to Solenoid 'A' and compare them with the transmission's line pressure sensor data.
6. If an internal fault is suspected, drain the transmission fluid and remove the transmission pan.
7. Visually inspect the internal wiring harness, connectors, and solenoid for damage.
8. Test the resistance of the suspect solenoid with a multimeter and compare it to the manufacturer's specifications (typically 5-7 Ohms for Hyundai pressure solenoids).
9. If the solenoid and wiring test good, the issue may be with the valve body itself or, rarely, the TCM.

Parts You'll Likely Need

• Automatic Transmission Control Solenoid (OEM #46313-4GXXX, 46313-4G200, 46313-4G100 (Varies by specific solenoid, must verify with VIN per TSB 22-AT-005H)) — This is the most likely component to have failed, either mechanically or electrically, causing the 'Stuck On' condition.
  Trusted brands: Hyundai Genuine
  OEM price range: $80-$110
  Aftermarket price range: $50-$90
• Transmission Valve Body Wiring Harness (OEM #46307-4GXXX (Verify with VIN, similar part numbers include 46307-3B650)) — Often replaced as a preventative measure with the solenoid, as recommended by Hyundai TSBs for similar issues, due to becoming brittle from heat cycles.
  Trusted brands: Hyundai Genuine
  OEM price range: $100-$200
• Automatic Transmission Fluid (SP4-M) (OEM #00232-19052 (or equivalent SP-IV M spec)) — The fluid must be drained to access the internal components and should be replaced with new, OEM-spec fluid. The A8LF1/2 transmission requires SP4-M fluid.
  Trusted brands: Hyundai Genuine
  OEM price range: $20-$30 per quart
• Transmission Oil Pan Gasket (OEM #45283-4GXXX, 45283-4G100 (Verify with VIN per TSB 22-AT-005H)) — The gasket should be replaced anytime the transmission pan is removed to prevent leaks.
  Trusted brands: Hyundai Genuine
  OEM price range: $40-$60
  Aftermarket price range: $20-$40

Related Codes That Often Appear With This One

• P0748 — This code is for 'Pressure Control Solenoid 'A' Electrical'. P0747 and P0748 often point to the same root cause related to the solenoid or its wiring. TSB 22-AT-005H directly addresses this code.
• P0746 — This code is for 'Pressure Control Solenoid 'A' Performance or Stuck Off'. It indicates a different failure mode of the same solenoid.
• P0741 — This code is for 'Torque Converter Clutch System - Stuck Off'. While a different circuit, it is also a solenoid-related code covered by TSB 22-AT-005H, indicating a similar failure pattern and repair procedure (solenoid and harness replacement).

Technical Service Bulletins (TSBs) & Recalls

• TSB 22-AT-005H: While this TSB does not list P0747 specifically, it covers numerous other solenoid electrical codes (like P074800, P074300, P074100) for the 2020+ Palisade (LX2) 3.8L. It instructs technicians to replace the faulty solenoid and the valve body harness, making its diagnostic logic highly relevant to a P0747 fault.
• TSB 20-AT-020H: This bulletin details the procedure for using the GDS Mobile scan tool to input oil pressure characteristic data into the Transmission Control Unit (TCU) after replacing the transmission or TCU. This step is crucial for optimizing shift quality and reducing the transmission's relearning period.

Platform-Specific Known Issues

• A Reddit user with a Hyundai reported getting a P0741 code (a related solenoid issue) and referenced TSB 22-AT-005H. Another user, identifying as a technician, commented that for this code they have had to replace the entire transmission on some vehicles even after replacing the solenoid per the TSB.
• Another owner of a 2020 Palisade with 75,000 miles reported stuttering during acceleration that required a full transmission replacement under warranty.

Mechanic-Grade Diagnostic Values

• Pressure Control Solenoid Resistance — expected: 5-7 Ω. Failure: A reading of 0 Ω (short) or infinite/OL (open circuit) indicates a failed solenoid coil.
• On/Off Shift Solenoid Resistance (for comparison) — expected: ~10.5 Ω. Failure: Readings significantly outside this range suggest a fault in that solenoid.

Scan Tool Commands That Help

• Hyundai GDS (Global Diagnostic System): Actuation Test — To command the specific pressure control solenoid on and off while monitoring pressure data to see if it responds. This can confirm if the solenoid is mechanically stuck or electrically unresponsive.
• Hyundai GDS Mobile: Oil pressure characteristics Input (A/T Replacement) — This function is required after replacing the transmission or TCU. It transfers the unique hydraulic characteristics (from a QR code on the transmission) to the control module to ensure proper shift quality and reduce learning time.
• Hyundai GDS: Resetting Adaptive Values — After replacing a solenoid or valve body, this function should be used to clear the learned shift adaptations from the TCM, forcing it to relearn shift points with the new components.

Wiring & Ground Locations

• Transmission Ground Strap — Connects the transmission case to the vehicle chassis, often near the engine mount.. A corroded or loose ground strap (Part No. 91862-S1010) can cause erratic electrical behavior in all transmission sensors and solenoids, potentially leading to false codes or incorrect operation.
• Main Chassis Ground — A key ground point is a bolt located just below the positive terminal in the under-hood fuse box.. A poor main ground can affect the entire vehicle's electrical system, including the TCM, causing a variety of faults that may include transmission codes.
• Automatic Transaxle Control System Wiring — Wiring diagrams for the 2020+ Palisade are available through paid services, which show the pinouts for the TCM and the main transmission connector.. Technicians need a wiring diagram to perform continuity and voltage checks between the TCM and the pressure control solenoid connector to rule out a wiring fault.

Model Year Variations Within This Range

• 2023-2025: The Hyundai Palisade received a facelift for the 2023 model year, which included updated exterior styling and interior technology (new screen, steering wheel, etc.). However, the powertrain, including the Lambda II 3.8L V6 and the A8LF1 8-speed automatic transmission, remained mechanically unchanged from the 2020-2022 models. Therefore, the causes and fixes for P0747 are identical across the entire 2020-2025 range.

Diagnostic Flowchart

Other Known Issues on This Vehicle

Issues unrelated to this code that are worth knowing about as an owner of this generation:

• Excessive Wind/Whistling Noise from Doors/Mirrors 🟡 Low — Common on early production models (2020-2021). Noise typically appears at highway speeds (60+ mph). (Ref: TSB 21-01-003H (supersedes 19-BD-010H) describes adding foam pads and replacing weatherstripping to resolve the noise.)
• Tow Hitch Wiring Harness Fire Risk 🔴 High — Affects 2020-2022 models equipped with a genuine Hyundai accessory tow hitch. Debris and moisture can cause an electrical short in the harness module, posing a fire risk even when the vehicle is parked and off. (Ref: NHTSA Recall 22V633000 (Hyundai Recall 235). The remedy involves installing a new fuse and wire extension kit. Owners were advised to park outside until the repair was completed.)
• Foul Interior Odor ('Garlic' or 'Dirty Socks' Smell) 🟡 Low — Reported primarily in 2020-2021 Limited and Calligraphy trims with Nappa leather. The smell was traced to a manufacturing flaw in the imitation leather used on the headrests. (Ref: TSB 20-BD-018H instructs dealers to treat the headrests with an odor-neutralizing solution or replace them if the smell persists.)
• Motor Driven Power Steering (MDPS) Bearing Noise 🟠 Medium — A clicking or grinding noise may develop in the steering column. Affects 2020-2022 models. (Ref: TSB 22-ST-005H provides a procedure to replace the worm shaft bearing in the MDPS assembly.)
• Third-Row Side Curtain Airbag Improper Deployment 🔴 High — A recall was issued for a large number of 2020-2025 Palisades after compliance testing showed the third-row side curtain airbag may not deploy correctly, increasing injury risk. (Ref: Hyundai Recall 292. A remedy was still under development at the time of the recall announcement.)

Used vs. New Parts: Buying Guide for This Vehicle

When a used part is the smart pick: For this repair, sourcing a complete, low-mileage used transmission assembly from a reputable salvage yard can be a cost-effective alternative if diagnosis points to internal damage beyond a simple solenoid, such as a failed valve body or clutch packs. Buying individual used solenoids is not recommended due to the high labor cost to install them and the unknown remaining lifespan.

Donor-vehicle mileage cap: roughly under 60000 miles for the part to have meaningful remaining life.

What to inspect on the donor part:

• Verify the donor vehicle's VIN to ensure it's a 2020-2025 Palisade with the same engine and drivetrain (FWD or AWD).
• Check the service history of the donor vehicle if possible, looking for regular maintenance.
• Inspect the transmission fluid from the donor unit. It should be bright red and not smell burnt. Dark, brown, or metallic fluid indicates severe internal wear.
• Look for any external damage to the transmission case, connectors, or the oil pan.
• Ensure the QR code tag for the oil pressure characteristics is present and legible, as it's needed for programming the TCU.

OEM-only on this vehicle (don't cheap out):

• Transmission Control Solenoid
• Internal Wiring Harness
• Transmission Filter and Gaskets

Brands owners have reported issues with on this vehicle:

• Unbranded or generic solenoids and valve bodies from online marketplaces are frequently cited as having incorrect calibration, leading to persistent shifting issues.

Real Owner Stories

Aggregated from forums and TSBs cited above. Mileages and costs reflect what owners reported in those sources.

Related OBD-II Codes

• P0741 — A related solenoid performance code mentioned in TSB 22-AT-005H and owner reports; often shares the same root cause of a faulty solenoid or internal harness.
• P0743 — An electrical circuit code for the torque converter clutch solenoid, explicitly covered under the same diagnostic TSB (22-AT-005H) as other Palisade solenoid failures.
• P0748 — Pressure control solenoid 'A' electrical code; it is the electrical counterpart to the mechanical/stuck-on fault of P0747 and is addressed by TSB 22-AT-005H.
• P074100 — The specific 6-digit variant of the solenoid performance code used in Hyundai factory diagnostics and TSB 22-AT-005H.

Frequently Asked Questions