P0747 on 2020-2024 GMC Acadia: Pressure Control Solenoid 'A' Stuck On Causes & Fixes

What's Unique About the 2020-2024 Gmc ACADIA

For this generation of GMC Acadia and its platform mates with the 9T65 9-speed transmission, P0747 is frequently linked to specific, documented mechanical failures within the transmission rather than just a simple solenoid failure. 🎬 Watch: Understanding how a stuck pressure control solenoid triggers this code. Manufacturer bulletins point to issues like worn components within the valve body and out-of-round snap rings. In fact, GM has issued Special Coverage N242454441, extending the warranty to 15 years or 150,000 miles for certain vehicles due to a worn transmission control valve that causes this exact code.

Diagnostic Flowchart

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

Symptoms You May Notice

• Vehicle will not move when put in Drive or Reverse.
• Transmission defaults to a single gear (e.g., 5th gear) and will not shift (Limp Mode).
• Harsh or jerky gear shifts, especially from Park into gear.
• Delayed engagement when shifting from Park.
• Check Engine Light is illuminated.
• Slipping out of gear under load or acceleration.

Most Likely Causes

1. Worn Internal Valve Body Components 🔴 High Probability → Shop Transmission Valve Body GM has identified wear in the control valve body, specifically the feed limit valve, as a primary cause for this code on its 9- and 10-speed transmissions. The original aluminum valve can wear inside its bore, causing pressure loss that prevents other valves from moving correctly, leading to the 'stuck on' condition. This is the subject of GM's Special Coverage N242454441.
   How to confirm: A technician will confirm the presence of DTC P0747. If the vehicle is covered under Special Coverage N242454441, the dealer is instructed to replace the valve body assembly. Independent shops may perform a transmission fluid pressure test and inspect the valve body for wear.
   Typical fix: Replacement of the entire control valve body assembly is the official GM-sanctioned fix under warranty or special coverage. Alternatively, repair kits like the Sonnax 9T45-ZIP kit can be used to address the specific worn components within the valve body.
   Est. part cost: $200-$900
2. Failed Pressure Control Solenoid 'A' 🟡 Medium Probability → Shop Transmission Valve Body While the solenoid is what the code reports, experts note that outright electrical or mechanical failure of the solenoid itself is rare. More often, the solenoid is functioning correctly, but its action is ineffective due to hydraulic pressure loss from a worn valve body, making it a symptom rather than the root cause.
   How to confirm: A technician can test the solenoid's resistance with a multimeter and command it on/off with a professional scan tool to check for a response. However, even if the solenoid tests good, the problem may still lie in the valve body it controls.
   Typical fix: Replacement of the pressure control solenoid. This is often done as part of a valve body service, but replacing only the solenoid without addressing valve body wear will likely result in the code returning.
   Est. part cost: $150-$250
3. Out-of-Round Transmission Snap Rings ⚪ Low Probability → Shop Transmission Assembly A specific GM Technical Service Bulletin (TSB PIP5974E) identifies an issue with out-of-round 1-2-3-4-5-6 clutch snap rings. This defect is specific to transmissions built between October 1, 2023, and April 2, 2024, primarily affecting 2024 and 2025 model year vehicles.
   How to confirm: This requires checking the transmission's Julian build date. If it falls within the specified range (23274 to 24093) and P0747 is present, this is the likely cause. [TSB #PIP5974E] Physical confirmation requires internal transmission disassembly.
   Typical fix: Replacement of the affected internal snap rings. This is a major, labor-intensive repair requiring transmission removal and disassembly.
   Est. part cost: $50-$150
4. Low or Contaminated Transmission Fluid 🟡 Medium Probability → Shop Transmission Assembly Low fluid levels reduce hydraulic pressure, while contaminated or burnt fluid can cause solenoids and valves to stick or operate poorly. If fluid contains excessive clutch material, it points to a severe internal failure beyond just a valve body issue.
   How to confirm: Check the transmission fluid level and condition. Fluid that is dark, smells burnt, or contains metallic debris indicates a serious internal problem.
   Typical fix: Perform a transmission fluid and filter change. If the fluid is heavily contaminated, a full transmission inspection is required, and a simple fluid change will not solve the problem.
   Est. part cost: $100-$250

Rare But Worth Checking

• Faulty Body Control Module (BCM) or Wiring: → Shop Body Control Module According to TSB #PIP5697B/D/E, a faulty BCM can trigger a false P0747. The issue occurs if the BCM fails to supply voltage to the TCM on circuit 5985 for at least 15 seconds after shutdown, preventing a proper power-down self-test. The code then sets on the next startup. Diagnosis involves checking voltage at BCM connector X4, terminal 22.
• Faulty Transmission Control Module (TCM): → Shop Transmission Assembly While uncommon, the TCM itself can fail, sending an incorrect signal that keeps the solenoid energized. This is usually diagnosed after all other mechanical and wiring issues have been eliminated.
• Broken Clutch Piston Return Spring: GM Engineering Information bulletin PIE0720A notes that a 'no move' condition with DTC P0746 or P0747 can be caused by a broken 1-2-3-4-5-6 clutch piston return spring. This is a major internal mechanical failure requiring transmission removal and disassembly to confirm.

Diagnosis Steps

1. Check the transmission fluid level and condition. If the fluid is low, top it off. If it is dark, burnt, or contains debris, a major internal inspection is needed.
2. Use a professional OBD-II scanner to check for any other transmission-related codes, particularly P0700 or P0746.
3. Consult TSBs. Check if the vehicle's VIN is covered by Special Coverage N242454441 for valve body replacement. Check the transmission build date for applicability of TSB PIP5974E regarding snap rings. [TSB #PIP5974E]
4. Investigate the BCM fault possibility per TSB PIP5697. Check if the code only sets during startup. If so, test the voltage on circuit 5985 at the BCM connector X4, terminal 22 after shutdown.
5. Inspect the transmission wiring harness and connectors for any visible damage, corrosion, or loose connections, paying close attention to the main harness connector on the transmission case where chafing can occur.
6. Perform a transmission fluid pressure test at idle. The pressure must be greater than 345 kPa (50 psi).
7. If valve body wear is suspected, remove and inspect the valve body for worn bores and sticking valves, particularly the feed limit valve.
8. If all mechanical and electrical components test good, the final step is to diagnose the Transmission Control Module (TCM).

Parts You'll Likely Need

• Transmission Control Valve Body (OEM #24043133) — This is the most common point of failure for this code on this platform, due to documented issues with worn internal valves. Replacement is covered for many vehicles under GM's Special Coverage N242454441.
  Trusted brands: ACDelco
  OEM price range: $600-$1200
  Aftermarket price range: $400-$800
• Valve Body Repair Kit (OEM #Sonnax: 9T45-ZIP) — Aftermarket kits like the Sonnax Zip Kit are designed to fix the root cause of valve body wear by replacing problematic valves and sealing pressure loss circuits, often for less than a full valve body replacement.
  Trusted brands: Sonnax
  OEM price range: N/A
  Aftermarket price range: $150-$250
• Transmission Pressure Control Solenoid — The solenoid itself can fail, though it's often a symptom of a larger valve body problem. It is typically replaced during a valve body service.
  Trusted brands: ACDelco
  OEM price range: $150-$250
  Aftermarket price range: $80-$150

Related Codes That Often Appear With This One

• P0700 — P0700 is a generic code indicating the Transmission Control Module (TCM) has requested the Check Engine Light to be turned on. It almost always appears alongside more specific transmission codes like P0747.
• P0746 — This code for 'Pressure Control Solenoid 'A' Stuck Off' is the counterpart to P0747. Both codes are often linked to the same root causes, such as the out-of-round snap rings mentioned in TSB PIP5974E.

Technical Service Bulletins (TSBs) & Recalls

• PIP5974E: Communicates possible transmission 1-2-3-4-5-6 snap rings out of round causing code p0746 or p0747.
• PIE0720A: Gathers information from technicians in regards to Vehicle Will Not Move When in Drive, Neutral and/or Reverse and DTCs P0746, P0747 Set.
• PIE0720: Requests technician feedback on vehicles with P0746/P0747 and a no-move condition.
• PIP5697B/D/E: Details a BCM or wiring fault that can cause a false P0747 at engine start-up.
• Special Coverage N242454441: Extends warranty coverage for valve body replacement to 15 years/150,000 miles for this specific issue.

Platform-Specific Known Issues

• Special Coverage N242454441: GM issued this special coverage for certain vehicles experiencing P0747 and related symptoms due to a worn transmission control valve. The coverage extends the warranty for this specific condition to 15 years or 150,000 miles, whichever comes first. The repair typically involves replacing the control valve body assembly.
• ETRS vs. Non-ETRS Valve Bodies: The 9T65 transmission was built with two types of valve bodies: ETRS (Electronic Transmission Range Select) for vehicles with button or dial shifters, and Non-ETRS for vehicles with a traditional mechanical shift lever. The 2020-2024 GMC Acadia uses the ETRS version. The valve bodies are not interchangeable, so it is critical to use the correct part for the specific vehicle.

Mechanic-Grade Diagnostic Values

• Pressure Control Solenoid (PWM type) resistance — expected: 3-8 Ohms. Failure: A reading outside this range (e.g., open circuit/infinite resistance or shorted/0 ohms) indicates a failed solenoid coil.
• On/Off type Shift Solenoid resistance — expected: 20-40 Ohms. Failure: A reading outside this range indicates a failed solenoid coil. This is for reference, as the P0747 solenoid is a PWM type.
• Transmission Line Pressure at Idle — expected: Greater than 345 kPa (50 psi). Failure: Pressure below 50 psi indicates a potential issue with the pump, valve body, or a major leak.
• Transmission Fluid Level Check Temperature — expected: 85–95°C (185–203°F). Failure: Checking the fluid level outside this temperature range will result in an inaccurate reading (too high if cold, too low if hot), potentially masking or causing problems.

Scan Tool Commands That Help

• GDS2 (or equivalent professional scanner): Solenoid Cleaning / Solenoid Dither Function — The T87A TCM performs a 'dither' or buzzing of the solenoids during a power-down sequence to clean them. A technician can listen for this after shutting the vehicle off. A lack of this sound could point to the BCM power-off issue noted in TSB PIP5697.
• GDS2 (or equivalent professional scanner): Live Data Monitoring during Road Test — While accelerating with a steady 15-20% throttle, monitor parameters like 'Command Gear', 'PC Sol. 2 Pressure Cmd.', 'TCC PC Sol. Pressure Cmd.', etc., to see if the commanded states match the vehicle's behavior. This helps isolate discrepancies between what the TCM is ordering and what the transmission is doing.
• GDS2 (or equivalent professional scanner): Transmission Service Fast Learn Procedure — This procedure should be performed after replacing the valve body or solenoids to reset and relearn adaptive values. Per GM Bulletin 20-NA-136, it's also used if a DTC was only found in History and could not be reproduced.

Wiring & Ground Locations

• TCM (TEHCM) — The Transmission Control Module is integrated into the valve body assembly (as a TEHCM - Transmission Electro-Hydraulic Control Module) inside the transmission. It is not a separate, externally mounted unit.. Because the TCM and solenoids are one unit, a failure of either component often requires replacement of the entire valve body assembly.
• Main Transmission Harness Connector — On the outside of the transmission case, where the main vehicle harness connects to the internal transmission components (TCM/solenoids).. This harness is a known chafe point on Acadia and similar platforms. Wires can rub through and break, causing loss of communication with the TCM, erratic shifting, and various fault codes.
• G113 — On the left side of the engine, located at an engine-to-transmission stud.. This is a primary ground point for the transmission assembly. A poor connection here can cause a wide range of electrical faults within the transmission, including erratic solenoid behavior and false codes.
• BCM Connector X4, Terminal 22 — At the Body Control Module (BCM).. This specific terminal supplies power to the TCM for its power-down self-test. A voltage check here is required to diagnose the rare BCM fault that can cause a false P0747.

Real Owner Repair Stories

• Reddit user on r/Silverado (2017 Silverado 1500 w/ 8-speed 8L90 transmission (72k miles)) — Stopped at a light, took foot off brake, Check Engine Light came on. Engine revved with no movement, then slammed into 1st gear and would not shift up. Code P0747 was present.
  ❌ Tried (didn't work) Initially ignored the problem after it seemed to resolve itself.
  ✅ What actually fixed it The initial owner found that turning the truck off and back on made it drive and shift fine, with the light turning off after a few key cycles. However, another user with a 2019 model commented that they ignored the same initial symptom and it occurred more frequently, eventually requiring a $6,000 transmission rebuild. A third user stated a dealer software update fixed their issue. This indicates the fault can be intermittent at first but may lead to catastrophic failure if not addressed.

"I Checked Everything" — The Actual Cause

• A classic example for this code is when the solenoid tests good, the wiring is intact, and fluid pressure seems okay, but the code persists. The cause can be a faulty Body Control Module (BCM) that fails to supply power to the TCM for at least 15 seconds after the ignition is turned off. This prevents the TCM from completing its power-down solenoid cleaning and testing cycle ('dither'). The TCM then flags a P0747 on the next startup, mistaking the incomplete test for a stuck solenoid.

OEM Part Supersession History

• 24293253, 24043757 → 24045659 — Part revision to address internal wear and performance issues. This part is for 'Non-ETRS' (mechanical shifter) models.
  Heads up: This part is NOT for the GMC Acadia, which uses an ETRS (Electronic Transmission Range Select) valve body, such as part number 24043133. Using a Non-ETRS valve body in an ETRS vehicle will not work.

Model Year Variations Within This Range

• 2024-2025 (transmissions built between Oct 2023 - Apr 2024): A specific batch of 9T transmissions were built with out-of-round 1-2-3-4-5-6 clutch snap rings, as identified in TSB PIP5974E. This manufacturing defect is a direct cause of P0747 and requires internal transmission repair, which is different from the more common valve body wear issue on earlier models. [TSB #PIP5974E]