P0747 on 2018-2020 Buick Envision: Pressure Control Solenoid 'A' Stuck On Causes and Fixes

What's Unique About the 2018-2020 Buick ENVISION

Unlike many vehicles where P0747 points directly to a failed solenoid or valve body, on the 2018-2020 Buick Envision, General Motors has issued Technical Service Bulletins (TSBs) identifying a very different root cause. These bulletins state the code can be falsely triggered because the Body Control Module (BCM) fails to supply proper voltage to the TCM for at least 15 seconds after engine shutdown. This prevents the TCM from completing its power-down self-test. On the next engine start, the TCM sees incomplete data and incorrectly sets P0747. This means an electrical problem outside of the transmission can mimic a serious internal fault, making correct diagnosis essential to avoid unnecessary repairs.

Diagnostic Flowchart

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

Symptoms You May Notice

• Harsh, jerky, or delayed gear shifts.
• Transmission getting stuck in a single gear (limp mode).
• Vehicle may not move when put in Drive or Reverse.
• Check Engine Light or Transmission Warning Light is on.
• Engine may stall when coming to a stop.
• Reduced fuel economy.
• Transmission overheating.

Most Likely Causes

1. Body Control Module (BCM) or Wiring Fault 🔴 High Probability This is a documented issue in GM Technical Service Bulletins #PIP5697B and #PIP5697E. The BCM fails to supply ignition voltage to the TCM/ECM for at least 15 seconds after shutdown, preventing a power-down self-test and causing a false P0747 on the next startup.
   How to confirm: A technician should follow TSB PIP5697E. This involves checking if the code sets during engine cranking or shutdown. The key diagnostic step is to verify the ignition voltage at BCM connector X4, terminal 22 (circuit 5985). It must remain within 4.0 volts of battery voltage for at least 15 seconds after the ignition is turned off. If voltage is low or absent, inspect circuit 5985 for opens or high resistance, often found under the driver's sill plate.
   Typical fix: Repairing the specific wiring circuit (e.g., circuit 5985) or replacing and reprogramming the Body Control Module if the circuit is intact.
   Est. part cost: $50-$600
2. Failed Transmission Control Valve Body 🟡 Medium Probability GM has acknowledged valve body wear causing P0747 on other models, and it's a common failure point in modern automatic transmissions. Debris or wear in the valve bores, particularly the feed limit valve, can cause valves to stick, leading to pressure control issues.
   How to confirm: A technician will use a scan tool to monitor transmission pressures and command the solenoid. Inspecting the transmission fluid for excessive clutch material or a burnt smell is also a key indicator. A Reddit user with a similar GM vehicle confirmed their P0747 was fixed by replacing the valve body under TSB 24-NA-088.
   Typical fix: Replacement of the transmission control valve body assembly and reprogramming the transmission control module. In some cases, the valve body may be repaired with updated components like a steel feed limit valve. 🎬 See how this updated valve fixes common GM valve body issues.
   Est. part cost: $400-$900
3. Internal Mechanical Failure (Broken Clutch Piston Return Spring) ⚪ Low Probability GM Engineering Information bulletin #PIE0720 identifies this as a potential cause on related platforms (including the Envision) when the vehicle will not move and sets code P0747 and/or P0746. The spring is for the 1-2-3-4-5-6 clutch.
   How to confirm: This is a diagnosis of last resort after electrical and valve body issues are ruled out. It requires transmission removal and disassembly to visually inspect for the broken spring.
   Typical fix: A complete transmission rebuild or replacement. The spring itself is an inexpensive part (e.g., GM Part #24250301), but the labor to access it is extensive. 🎬 Watch this teardown to see the internal complexity of the 9T50.
   Est. part cost: $2000-$4500
4. Low or Dirty Transmission Fluid ⚪ Low Probability
   How to confirm: Check the transmission fluid level and condition according to the service procedure, as these transmissions are sealed. The fluid should be at the correct level, red in color, and free of debris or a burnt smell. Contaminated fluid can clog solenoids and passages.
   Typical fix: Perform a transmission fluid drain and fill, or a complete fluid flush if the fluid is heavily contaminated. Replace the transmission filter.
   Est. part cost: $100-$300

Rare But Worth Checking

• Fatigued Solenoid Retaining Clip:

Diagnosis Steps

1. Verify the code with a professional OBD-II scanner capable of reading transmission data.
2. Check for Technical Service Bulletins (TSBs) related to P0747 for your vehicle's VIN. Specifically, check for the conditions of TSBs #PIP5697B and #PIP5697E (code setting on crank/shutdown).
3. If TSB conditions apply, test circuit 5985 at BCM connector X4, terminal 22. Verify voltage remains within 4.0V of battery voltage for at least 15 seconds after key-off. If not, inspect the circuit for opens/shorts or diagnose the BCM.
4. Inspect the transmission fluid level and condition. Dark, burnt, or debris-filled fluid suggests significant internal wear.
5. Inspect the transmission wiring harness and connectors for visible damage, corrosion, or loose connections.
6. Use a bi-directional scan tool to monitor transmission line pressure and to command Solenoid 'A' on and off. Observe if the solenoid responds electrically and if the pressure changes accordingly.
7. If electrical and fluid checks are inconclusive, further diagnosis of the valve body is required. This may involve inspection for worn bores or fatigued solenoid clips.
8. If the vehicle will not move, internal transmission inspection for a broken clutch piston return spring may be necessary as per GM bulletin #PIE0720.

Parts You'll Likely Need

• Body Control Module (BCM) — A documented cause of a false P0747 code on this vehicle per manufacturer TSBs due to improper power-down sequencing.
  Trusted brands: ACDelco
  OEM price range: $400-$600
  Aftermarket price range: $250-$450
• Transmission Control Valve Body (OEM #24045659 (Superseded by 24065460)) — A common failure point that causes pressure regulation issues, leading to code P0747. Wear in the valve bores is a known issue.
  Trusted brands: ACDelco
  OEM price range: $600-$900
  Aftermarket price range: $400-$700
• 1-2-3-4-5-6 Clutch Piston Return Spring (OEM #24250301) — A potential, though rare, cause of a no-move condition associated with P0747, requiring transmission disassembly.
  Trusted brands: ACDelco (GM Genuine)
  OEM price range: $6-$15

Related Codes That Often Appear With This One

• P0700 — P0700 is a generic code indicating the Transmission Control Module (TCM) has stored a fault code. It almost always appears alongside more specific transmission codes like P0747.
• P0746 — This code means "Pressure Control Solenoid 'A' Stuck Off". Seeing it with P0747 can indicate an erratic solenoid or a more complex hydraulic or electrical issue causing conflicting readings. GM bulletin PIE0720 notes that both codes can appear with a broken internal clutch return spring.

Technical Service Bulletins (TSBs) & Recalls

• PIP5697B: Communicates a possible BCM concern if DTC P0747 sets during engine cranking.
• PIP5697E: Communicates a possible BCM and/or circuit 5985 concern if DTC P0747 sets during engine shut down.
• PIE0720: Engineering Information bulletin linking P0747 and a no-move condition to a potentially broken internal 1-2-3-4-5-6 clutch piston return spring.

Platform-Specific Known Issues

• TSB #PIP5697B: Documents that DTC P0747 can be set during engine cranking in Park due to a BCM issue, not a transmission fault.
• TSB #PIP5697E: Explains that P0747 can set on the next startup if the BCM fails to supply voltage to the TCM/ECM on circuit 5985 for at least 15 seconds after shutdown, preventing a proper power-down self-test.

Mechanic-Grade Diagnostic Values

• BCM Power-Down Voltage to TCM — expected: Battery voltage (minus no more than 4.0V drop) present for at least 15 seconds after ignition is turned off.. Failure: Voltage drops out immediately or before 15 seconds have passed.
• 9T50 Variable Force Solenoid Coil Resistance — expected: 5.1 Ohms +/- 0.3 Ohms at 20°C (68°F).. Failure: An open circuit (infinite resistance) or a reading significantly outside the specified range.
• 9T50 On/Off Solenoid Coil Resistance — expected: 12.0 Ohms +/- 0.3 Ohms at 20°C (68°F).. Failure: A reading significantly outside the specified range.

Scan Tool Commands That Help

• GDS2 (GM Dealer Scan Tool): Solenoid Valve Diagnosis / Active Test — This function allows a technician to command individual pressure control solenoids on and off while monitoring the system's response. It is critical for determining if a solenoid is electrically functional and mechanically responding before condemning internal parts.
• GDS2 (GM Dealer Scan Tool): Transmission Service Adaptation (Fast Learn) — This procedure must be performed after replacing the valve body or the entire transmission to allow the TCM to learn the hydraulic characteristics of the new components for proper shift quality.

Wiring & Ground Locations

• Body Control Module (BCM) — Located in the center console, directly behind the lower panel on the passenger side of the vehicle.. The BCM is the source of the keep-alive voltage for the TCM's power-down self-test. A fault within the BCM is a primary cause for a false P0747 code on this vehicle.
• BCM Connector X4, Pin 22 (Circuit 5985) — This is a specific pin on a connector at the Body Control Module.. This is the specific circuit that must be tested for voltage during the 15-second window after ignition-off, as per TSB PIP5697E. A loss of voltage here confirms the electrical fault.
• BCM and TCM Grounds — Various locations on the chassis and engine block. Specific ground points (e.g., G-series numbers) should be referenced from a factory service manual.. Poor grounds for either the BCM or TCM can cause erratic behavior and voltage drops, potentially mimicking the fault described in TSB PIP5697E.

"I Checked Everything" — The Actual Cause

• A common scenario for P0747 on the 2018-2020 Envision is that standard transmission tests (checking fluid, commanding the solenoid with a scan tool) may show no issues. The solenoid may test perfectly fine on the bench with correct resistance. The actual cause, as identified in GM TSBs, is not a transmission component failure but an electrical issue where the Body Control Module (BCM) fails to supply voltage to the Transmission Control Module (TCM) for a sufficient time after the vehicle is shut off. This prevents the TCM from completing a self-test, leading it to set a false P0747 code on the next startup.

OEM Part Supersession History

• 24045659 (and others) → 24065460 — Part consolidation and likely internal updates to address wear or performance issues.
  Heads up: The replacement part 24065460 requires TCM programming and solenoid characterization after installation. The necessary data (PUN data) is included on an instruction sheet with the new valve body kit. Failure to perform this programming will result in poor transmission performance.