P0747 on 2017-2024 Chevrolet Suburban: Causes and Fixes for Pressure Control Solenoid 'A' Stuck On

What's Unique About the 2017-2024 Chevrolet SUBURBAN

This issue is particularly common on GM trucks and SUVs from this era, including the Suburban, which use the 8-speed (8L90) and 10-speed (10L80) automatic transmissions. The problem is so widespread that GM has issued multiple Technical Service Bulletins (TSBs) and a specific Special Coverage program (N242454441) to address P0747. The root cause is often not the solenoid itself, but wear within the valve body's internal bores, specifically around the feed limit valve 🎬 Watch: How this new valve design fixes common P0747 issues., which prevents proper pressure regulation. TSBs instruct dealers to replace the entire valve body assembly, and under the special coverage, this repair may be covered at no charge to the customer.

Diagnostic Flowchart

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

Generation note: This range covers the end of the 11th generation (2017-2020, K2YC platform) and the 12th generation (2021-2024, T1 platform) Suburban. The provided TSBs and owner complaints confirm this issue affects vehicles across both generations, particularly those with 8-speed (8L90) and 10-speed (10L80) automatic transmissions.

Symptoms You May Notice

• Check Engine Light (Malfunction Indicator Lamp) is on
• Transmission will not shift or gets stuck in one gear (often 5th gear).
• Harsh, erratic, or delayed shifting.
• Vehicle enters a default "limp mode" with reduced power.
• Reduced engine performance message on the dash.
• Transmission slipping.
• Vehicle feels like it is starting in a higher gear or fails to move from a stop.

Most Likely Causes

1. Faulty Transmission Control Valve Body 🔴 High Probability This is the primary cause on these vehicles. TSBs #24-NA-088 and Special Coverage #N242454441 identify wear within the valve body, causing a gradual loss of pressure, as the root of P0747. Aftermarket analysis points specifically to wear in the bores for the solenoid regulator valve and feed limit valve, which prevents them from sealing and operating correctly. It is a known design/manufacturing flaw.
   How to confirm: A professional technician will scan for code P0747, check for applicable TSBs and Special Coverage for the VIN, and inspect the transmission fluid. If the fluid is not full of clutch material, the diagnosis per GM's own bulletins is to replace the valve body.
   Typical fix: Replace the entire transmission control valve body assembly. According to Special Coverage #N242454441, this repair may be made at no charge for up to 15 years or 150,000 miles. More recent TSBs (like #25-NA-255 for 10-speeds) have introduced a more targeted repair of the valve body internals (new feed limit valve, spring, and spacer plate) instead of a full replacement.
   Est. part cost: $400-$1100
2. Low or Dirty Transmission Fluid 🟡 Medium Probability
   How to confirm: Check the transmission fluid level and condition. The fluid should be at the correct level, red/dark red in color, and not smell burnt. TSB #24-NA-088 provides visual guides: if the fluid is extremely dark and contains visible clutch material, the transmission has further internal damage beyond the valve body.
   Typical fix: Perform a transmission fluid and filter change using the correct fluid (e.g., DEXRON HP or similar). This is a good first step but is unlikely to solve the P0747 code if the internal valve body wear has already occurred.
   Est. part cost: $75-$200
3. Faulty Pressure Control Solenoid 'A' ⚪ Low Probability While the code directly names the solenoid, on these Suburbans the solenoid itself is rarely the point of failure. The issue is almost always the valve body housing that the solenoid actuates within. The solenoid is typically replaced as part of the complete valve body assembly, as it is not the root cause in isolation.
   How to confirm: A technician can test the solenoid's resistance, but this is often inconclusive as the issue is mechanical (sticking due to bore wear) rather than purely electrical. The official GM diagnostic path points to the valve body itself if code P0747 is present.
   Typical fix: The solenoid is replaced as part of the entire valve body assembly. It is not typically serviced separately for this specific problem.
   Est. part cost: $400-$1100

Rare But Worth Checking

• Wiring Harness Damage: Damage to the wiring leading to or within the transmission can cause a short or open circuit, mimicking a solenoid failure. This should be inspected before condemning expensive internal parts.
• Faulty Transmission Control Module (TCM): In rare cases, the TCM itself can fail. An early TSB for 2017 models suggested a calibration update could fix P0747, indicating software can be a factor. However, this is uncommon for later models and should only be considered after all other causes are ruled out.

Diagnosis Steps

1. Check the transmission fluid level and condition. If the fluid is low, dirty, or smells burnt, this indicates a potential problem but may not be the root cause of P0747.
2. Scan the TCM for all stored trouble codes. Note if P0747 is present, as this is the key trigger for GM's special coverage.
3. Check for any applicable TSBs or special coverage programs related to P0747 for your vehicle's VIN. TSBs #24-NA-088 and Special Coverage #N242454441 are highly relevant.
4. Inspect the transmission wiring harness and connectors for any visible damage, corrosion, or loose connections.
5. If other steps don't resolve the issue, follow the diagnostic procedures outlined in the relevant TSB. If P0747 is confirmed and there is no excessive clutch material in the transmission pan, the procedure directs replacement of the transmission control valve body.
6. After replacement, the new valve body must be programmed and undergo a relearn procedure (Service Fast Learn) with a factory scan tool.

Parts You'll Likely Need

• Transmission Control Valve Body Assembly (OEM #Varies by transmission (8L90 vs. 10L80) and year. Must be verified by VIN. Examples include 24299909 (8L90) or 24298758.) — This is the most common cause of P0747 on this vehicle, as confirmed by multiple manufacturer TSBs. The assembly includes the solenoids and the valve body which are prone to internal wear. Owners have reported these parts can be on national backorder, causing long repair delays.
  Trusted brands: ACDelco, GM Genuine Parts
  OEM price range: $600-$1100
  Aftermarket price range: $400-$800

Related Codes That Often Appear With This One

• P0796 — Pressure Control Solenoid 'C' Stuck Off. TSB #PIP5425A specifically notes that P0747 and P0796 can appear together, indicating a wider problem within the valve body or its control.
• P0777, P0797, P2715, P2724 — These are other pressure solenoid 'stuck on' codes. An early TSB (#PI1727A) for 2017 models grouped these codes together, suggesting a TCM calibration update as a potential fix, indicating a related control logic.

Technical Service Bulletins (TSBs) & Recalls

• 24-NA-088: Diagnostic tip for P0747, instructs to replace the valve body if fluid is clean.
• N242454441: Special Coverage program offering free valve body replacement for this issue.
• PIP5425A: Early investigation into P0747 and P0796 for 2017 models.
• 25-NA-255: Newer TSB for 10-speeds, directing an internal valve body repair instead of full replacement.

Platform-Specific Known Issues

• TSB #24-NA-088 specifically mentions replacing transmission control valve bodies to fix customer concerns of the Malfunction Indicator Lamp being on and the transmission not shifting due to DTC P0747.
• Special Coverage #N242454441 describes a 'gradual loss of pressure within the valve' causing harsh shifting and setting the P0747 code. It directs dealers to install a new control valve body at no charge to the customer for 15 years/150,000 miles.
• An early TSB, #PIP5425A for the 2017 model year, shows that GM was aware of issues setting codes P0747 and P0796 and was investigating a solution from the start of this vehicle generation.
• An owner of a 2023 model filed a complaint (NHTSA ODI #11685156) after their vehicle went into limp mode and the dealership confirmed error code P0747, demonstrating this is a real-world issue for owners.
• A recent TSB (#25-NA-255, for 10-speeds) has shifted the repair from full replacement to an internal fix, replacing the feed limit valve with an updated steel version and a stronger spring, indicating GM has isolated the specific internal failure point.

Mechanic-Grade Diagnostic Values

• 8L90 Variable Force Solenoid (VFS) / Pulse-Width Modulated (PWM) Solenoid Resistance — expected: 4.5 - 5.5 Ohms. Failure: A reading outside this range indicates a faulty solenoid coil.
• 8L90 On/Off Solenoid Resistance — expected: Around 12.0 Ohms. Failure: A reading significantly different from 12.0 Ohms suggests a faulty on/off solenoid.
• Transmission Fluid Temperature for Service Fast Learn — expected: 167°F (75°C) to 185°F (85°C). Failure: The scan tool will not permit the Service Fast Learn procedure to start if the fluid temperature is outside this range.

Scan Tool Commands That Help

• GDS2 (GM Dealer Scan Tool): Solenoid Valve Characterization Reprogramming (MCVM Operations) — Required after replacing the transmission assembly, valve body, individual solenoids, or the TCM. This procedure downloads unique performance data (based on PUN/TUN numbers) from GM's server to the TCM to ensure the new hardware is controlled correctly.
• GDS2 (GM Dealer Scan Tool): Transmission Service Fast Learn — Required after any major transmission repair, valve body replacement, or TCM programming. This 10-15 minute static procedure allows the TCM to learn the individual clutch apply pressures, which is critical for shift quality. It must be performed after the Solenoid Characterization is complete.
• GDS2 (GM Dealer Scan Tool): Solenoid Valve Diagnosis / Active Test — To individually command each solenoid on and off while monitoring pressure data. This helps determine if a solenoid is mechanically stuck or if the issue is in the wiring or TCM before disassembly.

Model Year Variations Within This Range

• 2021-2024 (10-Speed Transmissions): For vehicles with 10-speed transmissions (10L80/10L90), GM issued TSB #25-NA-255 which directs technicians to perform an internal repair of the valve body instead of a full replacement. This involves installing an updated steel Feed Limit Low Valve (PN 24059372), a higher tension spring (PN 24279142), and a new spacer plate assembly. This is a more targeted and cost-effective fix compared to the full valve body replacement typically performed on earlier models and 8-speeds.
• 2017-2024 (All): All 8L90 and 10L80/10L90 transmissions require specific characterization data to be programmed into the TCM when the valve body, solenoids, or transmission assembly are replaced. This is done by inputting the Part Unique Number (PUN) from the valve body/solenoid and the Transmission Unique Number (TUN) from the case into the GDS2 scan tool, which retrieves matching calibration data from GM's servers. Failure to perform this step will result in poor shift quality.