P2720 on 2018-2019 Chevrolet Camaro: Pressure Control Solenoid Circuit Fault Guide

What's Unique About the 2018-2019 Chevrolet CAMARO

For the 2018-2019 Camaro, this code is specifically called out in a manufacturer's Technical Service Bulletin (TSB #N182193520). The TSB notes that on a small number of vehicles equipped with the 8L45 or 8L90 8-speed automatic transmission, the main electrical connector to the transmission valve body may not have been fully seated during assembly. This creates a high-probability first step in diagnosis that is unique to this platform and can save significant time and money compared to immediately suspecting internal transmission failure.

Diagnostic Flowchart

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

Symptoms You May Notice

• Check Engine Light is on
• Transmission enters a "limp home" mode with limited gear availability
• Harsh, delayed, or erratic shifting
• Vehicle may feel stuck in one gear
• Increased fuel consumption

Most Likely Causes

1. Poorly Seated Transmission Electrical Connector 🔴 High Probability → Shop Transmission Assembly A known issue documented by GM in TSB #N182193520, stating the internal valve body solenoid connectors may not have been fully seated from the factory on vehicles with 8L45/8L90 transmissions.
   How to confirm: A technician must drop the transmission pan to access the two valve body solenoid connectors. Per the TSB, they will press firmly on each connector to ensure it is fully seated.
   Typical fix: Securely reseat the connector(s). The fix also requires replacing the transmission fluid that was drained and potentially exhaust gaskets if the exhaust was removed for access.
   Est. part cost: $0
2. Faulty Pressure Control Solenoid 'E' 🟡 Medium Probability → Shop Transmission Clutch Pressure Control Solenoid The 8L45/8L90 transmissions use multiple identical solenoids for different functions. Solenoid 'E' is designated as S1 in the valve body. Failure can occur from normal wear and tear.
   How to confirm: After confirming the internal connectors are secure, a technician must drop the transmission pan to access the solenoids. The suspect solenoid is tested for correct electrical resistance using a multimeter. The expected resistance is between 4.5 and 5.5 ohms. 🎬 Watch: Detailed walkthrough of the 8L90 valve body and solenoids.
   Typical fix: Replace the faulty solenoid. This often requires replacing the transmission pan gasket and refilling with new fluid. The specific solenoid for this function is GM part #24272282. After replacement, a 'Transmission Service Fast Learn' procedure must be performed with a scan tool.
   Est. part cost: $50-$150
3. Damaged Wiring Harness ⚪ Low Probability Forum users on Camaro6.com report instances of wiring harnesses being damaged by rubbing against the chassis or being burnt by aftermarket headers, leading to various electrical issues.
   How to confirm: Perform a continuity test on the wires running from the Transmission Control Module (TCM) to the transmission connector to check for opens or shorts. Visually inspect the harness for chafing or heat damage.
   Typical fix: Repair or replace the damaged section of the wiring harness.
   Est. part cost: $20-$200

Rare But Worth Checking

• Faulty Transmission Control Module (TCM): → Shop Transmission Assembly This is a rare cause and should only be considered after all other possibilities (wiring, connector, solenoid) have been thoroughly ruled out. A failure of the internal driver circuit for solenoid 'E' within the TCM can set this code. Communication codes like U0073 often accompany TCM issues.
• Low or Dirty Transmission Fluid: → Shop Transmission Assembly While less common for a specific circuit code, extremely low or contaminated fluid can cause erratic solenoid operation and should be checked as part of a comprehensive diagnosis.

Diagnosis Steps

1. Read the trouble codes with an OBD-II scanner and confirm P2720 is present. Note any other codes, especially P2718 or P0700.
2. Check for Technical Service Bulletins. TSB #N182193520 is the most important first step for this specific vehicle and code.
3. Per TSB #N182193520, the vehicle should be taken to a dealer or qualified shop. The procedure requires removing the transmission fluid pan to access the internal valve body solenoid connectors.
4. The technician will locate the two valve body solenoid connectors and press firmly on each to ensure they are fully seated.
5. The transmission pan is reinstalled (often with a new gasket), and the transmission is refilled with the correct fluid (DEXRON VI).
6. Clear the codes and test drive the vehicle to see if the code returns. If it does not, the issue is resolved.
7. If the code returns, the next step is to test the individual solenoids. A technician will identify Pressure Control Solenoid 'E' (S1) and test its resistance with a multimeter. The expected reading is 4.5-5.5 Ohms.
8. If the solenoid fails the resistance test, it will be replaced. After replacement, a 'Solenoid Valve Characterization Reprogramming' and a 'Transmission Service Fast Learn' must be performed using a dealer-level scan tool.
9. If the solenoid tests good, the internal and external wiring harness will be inspected and tested for continuity and shorts from the TCM to the transmission connector.
10. If all wiring and solenoids are confirmed to be good, the Transmission Control Module (TCM) may be diagnosed as the fault, though this is the least likely cause.

Parts You'll Likely Need

• Pressure Control Solenoid (S1, 'E') (OEM #24272282) — If reseating the connectors doesn't work, the solenoid itself is the next most likely component to have failed. This solenoid is used in multiple positions in the 8L45/8L90 valve body.
  Trusted brands: ACDelco (GM Genuine)
  OEM price range: $80-$150
  Aftermarket price range: $50-$100
• Automatic Transmission Pan Gasket — Required to be replaced anytime the transmission pan is removed to access internal components like the solenoids.
  Trusted brands: ACDelco, Fel-Pro
  OEM price range: $30-$50
  Aftermarket price range: $15-$30
• Automatic Transmission Fluid (OEM #19355656 (ACDelco DEXRON VI)) — Fluid must be replaced after dropping the transmission pan. Use only the fluid specified for your transmission. TSB #N182193520 lists this part number for the repair.
  Trusted brands: ACDelco
  OEM price range: $10-$15 per quart
  Aftermarket price range: $8-$12 per quart

Related Codes That Often Appear With This One

• P2718 — TSB #N182193520 explicitly states that both P2718 and P2720 can be set by the same issue of a poorly seated electrical connector.
• P0700 — This is a generic code indicating that the Transmission Control Module (TCM) has requested the Check Engine Light to be turned on. It will almost always be present alongside a specific transmission code like P2720.

Technical Service Bulletins (TSBs) & Recalls

• N182193520: States that the electrical connectors to the transmission valve body solenoids may not be fully seated, which can result in DTC P2718 or P2720 and cause the transmission to enter a 'limp home' mode. The fix requires dropping the transmission pan to access and reseat the connectors.

Platform-Specific Known Issues

• A GM Technical Service Bulletin (#N182193520) was issued for a small number of 2018-2019 Camaros with the 8L45 or 8L90 transmission where the internal transmission valve body electrical connectors were not fully seated, directly causing code P2720 or P2718.

Mechanic-Grade Diagnostic Values

• Pressure Control Solenoid 'E' (S1) Resistance — expected: 4.5 - 5.5 Ohms. Failure: A reading outside this range (e.g., open circuit/infinite resistance or shorted/0 ohms) indicates a faulty solenoid.
• Transmission Fluid Temperature for Service Learn Procedure — expected: 167°F - 185°F (75°C - 85°C). Failure: The scan tool will not allow the 'Transmission Service Fast Learn' procedure to run if the fluid temperature is outside this range.
• Solenoid Power Wire Voltage — expected: ~12 Volts. Failure: Significantly lower voltage suggests a problem in the wiring or the TCM, not the solenoid itself.

Scan Tool Commands That Help

• GDS2 (GM Dealer Scan Tool): Transmission Service Fast Learn — Required after replacing a solenoid, valve body, or the entire transmission to allow the TCM to learn the hydraulic characteristics of the new components and ensure proper shift quality.
• TIS2Web/SPS (Service Programming System): Solenoid Valve Characterization Reprogramming — Required when replacing a solenoid, valve body, or transmission. The technician must input the new part's unique number (PUN or TUN) to load its specific performance data into the TCM. Failure to do so will result in poor performance.

Wiring & Ground Locations

• Transmission Control Module (TCM) — The TCM for the 8L90 is an externally mounted module, not inside the transmission pan. On similar GM truck platforms, it is often found near the brake booster in the engine bay.. Since the TCM provides power and ground control to the solenoid, its connections and internal driver circuits are a potential point of failure for a 'circuit low' code.
• Main Transmission Electrical Connector — A 20-way electrical connector on the outside of the transmission case that connects the main vehicle harness to the transmission's internal components.. This is the primary interface between the TCM and the solenoids. A fault here can affect multiple components, though the TSB for P2720 points to an internal connector issue.
• Main Engine/PCM Ground — On many GM platforms, a critical ground wire runs from the main wiring harness to a 10mm bolt on the engine block.. Corrosion or a loose connection at this primary ground point can cause a wide range of difficult-to-diagnose electrical issues, including erratic shifting and performance problems that could be mistaken for a component failure.

OEM Part Supersession History

• 24272282 → 24044716 — Unknown
  Heads up: This supersession is noted on an eBay listing from a non-OEM seller and is not officially confirmed. Most official parts sources still list 24272282 as the correct part. Caution should be used; verify the part number with a GM dealer.