Due to incorrect software in the Data Communication Module (DCM) in your vehicle, the DCM cannot connect to the 4G cellular service. Therefore, after the 3G cellular service was sunset, voice communication with service providers when using connected services like Emergency call and Roadside assistance, is not available.
full bulletin at NHTSA ↗2021 Toyota Supra electrical problems
moderate 8 complaints filed with NHTSA · avg repair $850 · see electrical across all vehicles →
Complaints
8
Recalls
0
Avg fix
$850
When does it fail?
Of the 8 electrical complaints filed for the 2021 Toyota Supra, here's the actual mileage breakdown — failures cluster heaviest at 25,000-50,000 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.
Is there a fix? Manufacturer service bulletins
The manufacturer has issued service bulletins covering electrical 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.
Due to incorrect software in the Data Communication Module (DCM) in your vehicle, the DCM cannot connect to the 4G cellular service. Therefore, after the 3G cellular service was sunset, voice communication with service providers when using connected services like Emergency call and Roadside assistance, is not available.
full bulletin at NHTSA ↗TECHNICAL INSTRUCTIONS FOR LIMITED-SERVICE CAMPAIGN 24TD04 DATA COMUNICATION MODULE (DCM) UPDATE CERTAIN 2020 - 2023 SUPRA
full bulletin at NHTSA ↗Due to incorrect software in the Data Communication Module (DCM) in your vehicle, the DCM cannot connect to the 4G cellular service. Therefore, after the 3G cellular service was sunset, voice communication with service providers when using connected services like Emergency call and Roadside assistance, is not available.
full bulletin at NHTSA ↗Due to incorrect software in the Data Communication Module (DCM) in your vehicle, the DCM cannot connect to the 4G cellular service. Therefore, after the 3G cellular service was sunset, voice communication with service providers when using connected services like Emergency call and Roadside assistance, is not available.
full bulletin at NHTSA ↗Source: NHTSA manufacturer communications. Bring the bulletin number to your dealer or shop.
What owners are reporting 8 most recent
Vehicle fails to restart after automatic ignition shut off when pressure is removed from brake pedal causing vehicle to shift into neutral without engine power. Vehicle also fails to start showing "starter system fault" error.
Passenger side low beam headlight suddenly stopped working on the highway. Symptoms same as Toyota recall 19TA20, however vehicle is not part of the recall campaign. Vehicle displayed error "Right low beam malfunction". Dealership is not willing to investigate under recall coverage.
I own a new 2021 Toyota Supra and along with other owners of this new model, there is a safety issue that has been identified. There is a repeating issue with unresponsive/unpredictable throttle behavior for me and other Toyota Supra owners. It only happens on a cold start, when going in reverse on a slope (exiting the garage) and when traction control gets engaged (the wheel gets in the air for…
The contact owns a 2021 Toyota Supra. The contact stated that while attempting to start the vehicle the engine did not immediately start and the message regarding a starter malfunction had displayed. The vehicle was later started and driven to the local dealer who diagnosed that the start needed to be replaced. The vehicle was not yet reparied. The manufacturer was notified of the failure, but no…
Odometer Fraud. The contact purchased a 2021 Toyota Supra. The contact stated that after obtaining the vehicle's Carfax history report, it was discovered that there was a mileage discrepancy. The vehicle was a private dealer sale. At the time of purchase, the vehicle mileage was 47,764, and after receiving Carfax history report, it was discovered that the mileage was 72,650.
See attached document for complaint. Toyota Motor North America, Inc. has failed or is unable to remedy the safety recall (NHTSA Recall No. 25V-636), issued on 26 September 2025, for my 2021 Toyota Supra within a reasonable period of time. According to the non-dated letter from Toyota, the recall is for a defect in the engine starter relay that may catch fire without warning “during vehicle…
The contact owns a 2021 Toyota Supra. The contact received notification of NHTSA Campaign Number: 25V636000 (ELECTRICAL SYSTEM); however, the part to do the recall repair was unavailable. The local dealer was contacted, and it was confirmed that the part was not yet available. The contact stated that the manufacturer had exceeded a reasonable amount of time for the recall repair. The manufacturer…
The contact owns a 2021 Toyota Supra. The contact received notification of NHTSA Campaign Number: 25V636000 (Electrical System); however, the part to do the recall repair was not yet available. The dealer was contacted. The contact disconnected the battery after parking the vehicle outside to prevent the vehicle from catching on fire. Additionally, the contact expressed that he was making monthly…
Had electrical trouble with your 2021 Toyota Supra?
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 electrical problem on the 2021 Toyota Supra?
It's a documented issue but not catastrophic. 8 complaints have been filed. Repairs average $850 and most owners catch it before it causes a breakdown.
At what mileage does the electrical typically fail?
Based on the 8 complaints filed, electrical issues most often appear around 53,072 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 $850 for electrical 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 electrical?
No active recalls currently cover electrical 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/2021/Toyota/Supra.
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.