P2714 on 2021-2025 Cadillac CT5: Causes, Symptoms, and Fixes

What's Unique About the 2021-2025 Cadillac CT5

For the Cadillac CT5 equipped with the 10-speed automatic transmission (RPO codes MHS, MHO, MQC, etc.), P2714 is not just a generic solenoid code. General Motors has issued a Preliminary Information bulletin (PIP6008E) that directly links this code to a mechanical failure: an 'Input Internal Gear Retainer Ring' inside the transmission can become dislodged. This causes the Input Internal Gear to separate from the Direct Overdrive Sun Gear Shaft, leading to severe symptoms like the loss of reverse gear. This issue can occur even on very new vehicles with under 1,500 miles, making it a critical, vehicle-specific problem rather than a typical wear-and-tear solenoid failure.

Diagnostic Flowchart

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

Symptoms You May Notice

• Complete loss of reverse gear (engine revs as if in neutral).
🎬 See a real-world example of a 10-speed transmission failure
• Check Engine Light and/or transmission warning messages on the dashboard (e.g., 'Service Transmission Now').
• Harsh or erratic shifting.
• Sudden loss of forward propulsion, feeling as if the transmission slipped into neutral.
• Vehicle may enter a 'limp mode' with limited gear availability to prevent further damage.
• DTC P2714 present with or without the ability to engage reverse.

Most Likely Causes

1. Dislodged Internal Retainer Ring 🔴 High Probability As identified in GM Preliminary Bulletin #PIP6008E, the Input Internal Gear Retainer Ring can become dislodged, causing the Input Internal Gear to separate from the Direct Overdrive Sun Gear Shaft. This is a known manufacturing or assembly defect on the 10-speed (MHS/MHO/MQC and others) automatic transmission family.
   How to confirm: A technician must perform an internal transmission inspection to verify if the retainer ring (item #502 in service documents) is dislodged. This requires significant disassembly. The issue is most commonly seen on transmissions with fewer than 1,500 miles.
   Typical fix: The transmission must be opened to replace the dislodged retainer ring and inspect for any related component damage. Depending on the extent of the damage, a full transmission replacement may be necessary.
   Est. part cost: $5 - $20 for the ring itself, but potential for thousands if other hard parts are damaged.

Rare But Worth Checking

• Faulty Pressure Control Solenoid 'D': While the TSB points to a mechanical failure, a standard electrical fault with the solenoid itself is still possible, though less likely on this platform given the known issue. Diagnosis should rule out the TSB issue first.
• Low or Contaminated Transmission Fluid: Extremely low or dirty fluid can cause a variety of pressure-related codes and shifting problems. This should be checked as a preliminary step, but it is unlikely to be the root cause if the primary symptom is a complete loss of reverse on a low-mileage vehicle.
• Wiring or Connector Issue: A damaged wire or loose connector between the TCM and the transmission valve body could interrupt the signal to the solenoid, triggering the code. This is a possibility but is less probable than the known mechanical fault.
• Faulty Transmission Control Module (TCM): In very rare cases, the TCM itself can fail and stop sending the correct command to the solenoid. This is typically diagnosed only after all other possibilities have been exhausted.
• Sticking Valve in Valve Body: Debris or wear can cause a clutch regulator valve to stick in the valve body, leading to pressure control issues that can trigger P2714. Another TSB, 24-NA-009, discusses this for other GM vehicles but highlights it as a possible cause for this code.

Diagnosis Steps

1. Confirm the presence of DTC P2714 using a high-quality OBD-II scanner.
2. Interview the driver about the specific symptoms, paying close attention to whether reverse gear is functional.
3. Check for any applicable Technical Service Bulletins (TSBs), specifically GM #PIP6008E.
4. Check the transmission fluid level and condition to rule out simple issues.
5. If symptoms align with TSB #PIP6008E (especially loss of reverse on a low-mileage vehicle), the primary diagnostic step is to recommend an internal transmission inspection to check for the dislodged retainer ring (item #502).
6. If the TSB does not apply or the retainer ring is intact, proceed with standard electronic diagnostics: test the solenoid's resistance, check the wiring for continuity, and verify the TCM is commanding the solenoid correctly.

Parts You'll Likely Need

• Input Internal Gear Retainer Ring (OEM #8642220 or 24231268 or 24263704) — This is the specific part identified in GM TSB #PIP6008E as the root cause of the mechanical failure that triggers P2714. Part number may vary; confirmation with dealer via VIN is required.
  Trusted brands: ACDelco, GM Genuine Parts
  OEM price range: $5-$20
  Aftermarket price range: $5-$15
• Complete Transmission Assembly — If the retainer ring failure caused significant damage to other internal components (gears, shafts, case), replacing the entire transmission may be more cost-effective or required. This is especially true if the failure occurs under warranty.
  Trusted brands: ACDelco, GM Genuine Parts
  OEM price range: $4000-$6000
  Aftermarket price range: $3000-$5000

Technical Service Bulletins (TSBs) & Recalls

• PIP6008E: Communicates a possible dislodged retainer ring for a DTC P2714, which may also cause a loss of reverse gear. Lists affected vehicles including CT5, Escalade, Silverado, Sierra, Tahoe, and Yukon.
🎬 Watch: Overview of the GM 10-speed transmission recall and affected models
• 24-NA-009: Discusses P2714 on other GM vehicles (with CVT transmissions) caused by a sticking clutch regulator valve in the valve body. While for a different transmission, it shows another potential mechanical cause for this code.

Platform-Specific Known Issues

• A known defect involving a dislodged internal retainer ring is the primary cause for P2714 on this platform, as documented in GM Preliminary Information Bulletin #PIP6008E.
• This failure is often observed in very low-mileage transmissions, sometimes under 1,500 miles.
• The 10-speed automatic transmission (co-developed with Ford) is used across a wide range of GM trucks and SUVs, many of which are also listed in the TSB.
• Another potential issue in the 10-speed family is premature check ball wear in the spacer plate, which can also lead to a no-reverse condition, though it may present with different DTCs.

Mechanic-Grade Diagnostic Values

• Pressure Control Solenoid (PWM) Resistance — expected: 3.0 - 8.0 Ohms. Failure: A reading outside this range indicates a failed solenoid coil.
• Shift Solenoid (On/Off) Resistance — expected: 20 - 40 Ohms. Failure: A reading outside this range points to a faulty shift solenoid.
• Transmission Fluid Temperature (for diagnostics) — expected: 167°F - 185°F (75°C - 85°C). Failure: Fluid level and diagnostic procedures like the Fast Learn must be performed within this temperature range for accuracy.

Hidden / Shadow Codes Worth Checking

• 7E9: This is not a fault code, but a menu header indicating the scanner is communicating with the Transmission Control Module (TCM). Basic scanners may display this, requiring the user to navigate into this menu to read the actual P-codes like P2714. (see via Basic OBD-II scanners or apps that don't automatically retrieve detailed codes from all modules.)

Scan Tool Commands That Help

• GDS2 (GM Techline Connect): Transmission Service Fast Learn — This procedure is required after replacing the transmission, valve body, or performing other major internal repairs. It allows the TCM to learn the hydraulic characteristics of the clutches and solenoids to ensure proper shift quality.
• GDS2 (GM Techline Connect): Solenoid Valve Diagnosis / Output Controls — Allows a technician to command individual solenoids on and off to verify electrical circuit integrity and solenoid mechanical response (often heard as a click). This is used to isolate a faulty solenoid when the TSB mechanical failure is not the cause.
• GDS2 / Data Bus Diagnostic Tool: Module Communication Check — To verify that the Transmission Control Module (TCM) is actively communicating on the CAN bus. An unresponsive TCM could indicate a power, ground, or module failure, which could be a rare cause of P2714.

Real Owner Repair Stories

• Reddit user Twigger-3559 (2021 Silverado 1500 3.0L Duramax (shares 10-speed transmission family)) — Hard shifting, followed by check engine light and vehicle entering limp mode. Required towing.
  ❌ Tried (didn't work) Replaced NOx sensor, Replaced Transmission Control Module (TCM) twice, Replaced wiring harness, Attempted to order a new valve body (on backorder)
  ✅ What actually fixed it The dealer determined a full transmission replacement was necessary. The vehicle was in the shop for a cumulative 105 days waiting for parts and resolution from GM.

OEM Part Supersession History

• Unknown → 24231268 — This is a common retaining ring used in multiple GM transmissions.
  Heads up: While listed for many GM transmissions, including as a 'Turbine Shaft Retaining Ring', it is one of the part numbers associated with the failure. A dealer must confirm the exact correct part number for the specific transmission build via VIN, as multiple rings are used internally.

Model Year Variations Within This Range

• 2020-2022: For some GM models with the 10-speed, including the related CT4, a recall was issued for a defective transmission control valve that could wear prematurely, causing pressure loss and harsh shifts. While not directly citing P2714, it points to widespread valve body and hydraulic control issues in early versions of this transmission family.