Certain vehicles listed above, may have a condition where the transmission control valve has worn, resulting in a gradual loss of pressure within the valve. The effects can cause harsh shifting, setting a service engine soon message, reduced engine performance or P0747 diagnostic trouble code. This special coverage covers vehicles that return after TCM Update Product Safety N242480630 and have P0747 condition described above for a period of 15 years or 150,000 miles (240,000 km), whichever occurs first, from the date the vehicle was originally placed in service, regardless of ownership. For vehicles covered by Vehicle Service Contracts, all eligible claims with repair orders on or after Marc
full bulletin at NHTSA ↗2020 Cadillac CT5 powertrain problems
severe 13 complaints filed with NHTSA · avg repair $2,500 · see powertrain across all vehicles →
Complaints
13
Recalls
0
Avg fix
$2,500
1crash
When does it fail?
Of the 13 powertrain complaints filed for the 2020 Cadillac CT5, here's the actual mileage breakdown — failures cluster heaviest at 0-25,000 mi.
0-25k
25-50k
50-75k
75-100k
100-125k
125-150k
150k+
Each bar shows the share of total complaints filed at that mileage range. Peak failure window highlighted. Some owners report problems earlier; some make it well past 150,000 miles symptom-free. Maintenance habits and driving conditions shift the curve as much as mileage alone.
What stands out
Powertrain accounts for 39% of every owner complaint on file for this vehicle — the dominant problem area across 3 categories tracked.
Is there a fix? Manufacturer service bulletins
The manufacturer has issued service bulletins covering powertrain on this vehicle — documented repair instructions, service campaigns, or warranty extensions sent to dealers. A TSB isn't a recall (it's not a free safety remedy), but it's the manufacturer acknowledging the issue and how to fix it.
This preliminary informational (PI) bulletin provides information to dealership personnel that may be helpful when addressing underbody component corrosion with customers.
full bulletin at NHTSA ↗Certain vehicles listed above, may have a condition where the transmission control valve has worn, resulting in a gradual loss of pressure within the valve. The effects can cause harsh shifting, setting a service engine soon message, reduced engine performance or P0747 diagnostic trouble code. This special coverage covers vehicles that return after TCM Update Product Safety N242480630 and have P0747 condition described above for a period of 15 years or 150,000 miles (240,000 km), whichever occurs first, from the date the vehicle was originally placed in service, regardless of ownership. For vehicles covered by Vehicle Service Contracts, all eligible claims with repair orders on or after Marc
full bulletin at NHTSA ↗This bulletin helps aid the tech in possible noise that may be normal or abnormal depending on the concern noted.
full bulletin at NHTSA ↗This bulletin provides information on identifying Non-GM Engine Calibrations for Gasoline Engines using the Tech 2 or GDS 2.
full bulletin at NHTSA ↗Source: NHTSA manufacturer communications. Bring the bulletin number to your dealer or shop.
The failure pattern owners describe
Owners consistently report transmission problems starting from the moment they bought these vehicles at 12,000 miles. The 10-speed 10L90 transmission exhibits delayed, jerky, and harsh shifting across all gear ranges, along with sluggish acceleration and strange noises. Some owners describe sudden power loss on the highway without warning lights—dangerous situations where the vehicle dropped from 65 mph to 10 mph or lost all propulsion.
Several owners discovered the transmission's control valve body was defective at purchase but dealers denied problems existed, even after multipoint inspections. When failures worsened, dealers diagnosed transmission damage from worn valve bodies and quoted full transmission replacement at owner cost.
GM issued recall 25V148000 (transmission control module reflash and monitoring software), which owners confirm is inadequate. Even after dealers performed the recall work, owners report the same power loss and shifting issues persist. Some dealers then refused additional repairs, citing branded titles or claiming the software fix is all GM will cover.
Separate complaints cite turbo failures at 55,000 miles on two different CT5s from the same owner, along with camshaft solenoid failure, EVAP sensor malfunction, traction control/StabiliTrack power loss events, and rear wheel lockup incidents. One owner reported sudden neutral shifts while driving that recurred after dealer service. GM customer support has been unresponsive to warranty claims for transmission damage caused by known valve body defects.
Failure modes owners describe
Transmission valve body/control valve defects
Faulty transmission control valve body in the 10-speed 10L90 automatic, causing harsh, delayed, jerky shifts and loss of power. Multiple owners report the defect was present from purchase but not disclosed. GM issued NHTSA Campaign 25V148000 (transmission monitoring software reflash), but owners report this recall remedy is inadequate and does not address the underlying valve body wear or transmission damage already incurred.
When: From purchase (12K miles in one case); typically 55K–70K miles or earlier
Symptoms owners cite: Delayed and jerky gear shifts (1–2, 2–3, 3–4, 4–5); Harsh/loud shifting; Slow and laggy acceleration; Loss of power during highway driving; Strange vibrations and noises; Transmission slipping and delay while shifting
Codes mentioned: P0451
Repairs/costs cited: Valve body replacement performed by dealer in at least one case; multiple owners report transmission replacement needed at owner expense. One owner's transmission was replaced in 2022 and failed again. Recall repair (software reflash) at dealership; dealers refused further work or transmission replacement citing branded title.
Recalls/TSBs owners mention: NHTSA Campaign 25V148000 (transmission control module reflash). GM denied full buyback/replacement in at least one case; customer support unresponsive to warranty claims for transmission damage caused by valve body failure.
Transmission pump failure
Transmission pump failed during highway driving, causing sudden loss of power and jerking at speed. Owner reports no warning lights appeared. Occurred on vehicle with two small children, presenting imminent crash risk.
When: Unspecified mileage; highway driving
Symptoms owners cite: Loss of power while driving at highway speeds; Jerking motion; No warning lights prior to failure
Repairs/costs cited: Diagnosed by dealer (Hennessey Cadillac); repair status not specified in narrative.
Transmission lockup / rear wheel lockup
Rear wheels locked up during normal driving, causing transmission damage and loss of vehicle control. In one case, vehicle slid on ice after momentary shift into Park. Owners report dealers initially diagnosed as transmission failure requiring replacement, but refused repair work citing branded title.
When: Approximately 65K miles and unknown mileage in separate cases
Symptoms owners cite: Rear wheels locked up; Vehicle unable to accelerate above 10 MPH; Reduced Power warning message displayed; Vehicle momentarily shifted into neutral/Park; Abnormal shaking and jerking during test drive
Repairs/costs cited: Transmission damage confirmed by dealer inspection; replacement needed but refused at owner expense or due to branded title. Recall repair (PCM reflash and transmission monitoring software) performed; did not resolve underlying mechanical damage.
Recalls/TSBs owners mention: NHTSA Campaign 25V148000 (PCM reflash and transmission monitoring software). GM advised no further assistance available.
Transmission shifting into neutral unexpectedly
Vehicle shifts into neutral without driver input while driving at any speed, causing complete loss of power and vehicle coasting to a stop. Occurs without warning and poses rear-end collision risk. Recall repair performed but issue unresolved after 10+ days at two separate dealerships.
When: Post-recall service; specific failure mileage not stated
Symptoms owners cite: Vehicle unexpectedly shifts into neutral while driving; Complete loss of power and coasting to stop; Occurs at any speed regardless of road conditions; Requires manual shift to Park to restart vehicle
Repairs/costs cited: Recall service performed at two Cadillac dealerships; unable to simulate issue or resolve complaint.
Recalls/TSBs owners mention: NHTSA Campaign 25V148000 recall performed; issue remains unresolved.
Engine solenoid failure (camshaft solenoid P0027)
Camshaft solenoid failure detected by dealer diagnostic; issue was present at purchase but not disclosed to buyer. Could cause engine stalling or hesitation.
When: Present at purchase; not disclosed
Symptoms owners cite: Potential engine stalling or hesitation
Codes mentioned: P0027
Repairs/costs cited: Repaired by dealer; specific parts/costs not provided.
EVAP system fuel tank pressure sensor failure (P0451)
Fuel tank pressure sensor malfunction triggered check engine light shortly after purchase. Affects emissions and presents potential fire risk from fuel vapor leaks.
When: Shortly after purchase
Symptoms owners cite: Check engine light illuminated; Fuel tank pressure sensor malfunction
Codes mentioned: P0451
Repairs/costs cited: Diagnosed by dealer; repair status not clearly stated.
Traction control/StabiliTrack failure with power loss
Traction control and StabiliTrack lights activate intermittently with sudden engine power loss. Vehicle speed drops from 80 mph to 20–25 mph without driver control, creating safety hazard especially in canyon driving.
When: September/October; failure occurs repeatedly
Symptoms owners cite: Traction control light illuminates; StabiliTrack light illuminates; Loss of engine power; Check engine light (multiple occurrences); Sudden speed drops from 80 to 20–25 mph without warning
Repairs/costs cited: Dealership cleared code and test drove 38 miles; no repair performed. Advised owner to return when lights are active. Unresolved after multiple service visits.
Turbocharger failure
Turbocharger failure reported by owner who owned two separate 2020 CT5 models, both failing at the same mileage (55K miles).
When: 55K miles (reported in both vehicles owned)
Symptoms owners cite: Turbo failure
Repairs/costs cited: Replacement needed; costs not specified.
Engine oil leak
Engine oil leak identified by dealer during recall repair inspection. Not diagnosed or repaired; manufacturer declined to provide assistance.
When: Identified at approximately 65K miles during recall service
Symptoms owners cite: Engine oil leaking
Repairs/costs cited: Identified at dealer but not repaired.
Recalls/TSBs owners mention: Manufacturer advised no assistance available.
Synthesized from 13 NHTSA owner complaints — unverified consumer allegations, summarized for patterns. The verbatim filings appear below.
What owners are reporting 8 most recent
this vehicle has had multiple check engine failures it has been in for service six times in a matter of months. In September I had Service Traction control/StabiliTrack lights come on and the car losses of engine power. I had it serviced again in October for the same issue it was at the dealership for 20 days all they did was clear the code and drove it 38 miles, including the technician driving…
The contact owns a 2020 Cadillac CT5. The contact stated that while driving approximately 65 MPH, the vehicle unexpectedly stopped without the brake pedal being depressed. The contact stated that the message "Reduced Power" was displayed on the instrument cluster. The contact was able to continue driving; however, the vehicle failed to accelerate above 10 MPH. The contact was able to drive the…
For no apparent reason my vehicle is shifting itself into Neutral while driving. The car will suddenly completely slow down to a stop and in order to restart the car, I have to put it in park. It doesn't matter what speed or the road condition, it simply comes to a slow stop because it is no longer in driving mode, it has shifted itself into Neutral. The recall has been serviced and after more…
Major safety Concern Faulty valve body and transmission dealership failed to disclose. Service manager drove vehicle with bent wheels. That is how the bent wheels were discovered. Not from inspection. Wheels evidently bent under dealership possession. 2020 Cadillac CT5 Vehicle financed at 12K Miles with certified pre owned, bumper to bumper, and powertrain warranties in February 2024 showed poor…
Two separate issues: One is being sold a vehicle with a Certified vehicle at 12K miles with a defective, faulty transmission which is a manufacturer defect from General Motors. 10-speed automatic transmission 10L90 model. Misrepresentation of a product. False advertisement of a product. Failure to disclose. Gross negligence. Unethical & Illegal business practices. Dealer & manufacturer fraud.…
I've owned 2 ct5 each one had their turbos go out at 55k miles each and valves bodies that need replacing around 70k for each vehicle
The contact owns a 2020 Cadillac CT5. The contact stated that while driving at various speeds, the transmission was slipping while shifting gear. Additionally, the contact stated that there was a delay while shifting gear. The check engine warning light remained illuminated intermittently. The vehicle was taken to a local dealer where the vehicle was diagnosed, and the contact was advised that…
Regarding NHTSA Campaign ID 25V148, GM recall N242480630. The recall was for a potential transmission control valve issue where some vehicles may be susceptible to excess wear over time, resulting in gradual loss of pressure within the valve that can cause harsh shifting. With the recall we finally knew what was wrong with the vehicle. We have a defective transmission control valve. The…
Had powertrain trouble with your 2020 Cadillac CT5?
File a complaint with NHTSA → It's free, official, and how every report above got here — owner filings are the federal safety record this page is built on.
Common questions
How serious is the powertrain problem on the 2020 Cadillac CT5?
It's a meaningful issue. 13 complaints have been filed and the failure mode causes operational problems for owners. Repairs average $2,500.
At what mileage does the powertrain typically fail?
Based on the 13 complaints filed, powertrain issues most often appear around 38,500 miles. Some report problems earlier; some make it well past 150,000 with no symptoms. Maintenance habits matter — vehicles that received timely fluid services and were not regularly overworked tend to last longer.
What does it cost to fix?
Independent shops typically charge around $2,500 for powertrain repairs on this vehicle. Dealer pricing tends to run 20-40% higher. The exact figure depends on the specific failure mode, parts availability, and your local labor rates. If you're outside factory warranty, an extended service contract often covers this category.
Are there any recalls related to powertrain?
No active recalls currently cover powertrain issues on this vehicle. The complaints filed represent owner-reported failures that haven't risen to the level of a manufacturer-issued recall — but they're still worth knowing about before you buy or budget for repairs.
Related
Complaint and recall data sourced from the National Highway Traffic Safety Administration (NHTSA)
public records database. Verify the raw federal record at
nhtsa.gov/vehicle/2020/Cadillac/CT5.
Severity ratings are derived from reported crashes, fires, injuries, and fatalities. Repair cost estimates are
independent-shop national averages and may differ in your area. Some links on this page are affiliate links.