This bulletin provides a procedure on how to check for a battery drain utilizing the Picoscope and how to measure the load on the system that may be causing a drain.
full bulletin at NHTSA ↗2021 GMC Terrain electrical problems
moderate Owners of the 2021 GMC Terrain have filed 5 NHTSA complaints about the electrical at roughly $850 to repair (U.S. federal records, as of July 2026). Source: NHTSA Office of Defects Investigation. See electrical across all vehicles →
Complaints
5
Recalls
0
Avg fix
$850
| Model year | electrical complaints |
|---|---|
| 2017 Terrain | 6 |
| 2018 Terrain | 29 |
| 2019 Terrain | 23 |
| 2020 Terrain | 21 |
| 2021 Terrain (this page) | 5 |
| 2022 Terrain | 8 |
| 2023 Terrain | 5 |
| 2024 Terrain | 4 |
| 2025 Terrain | 3 |
What stands out
No new NHTSA electrical complaint has been filed on this vehicle in over 4 years — the issue may be aging out of the active population.
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.
This service bulletin provides information on the proper Reflective High Temperature Heat and/or Insulating Tape to use for certain repairs, such as Wiring Harness Repairs.
full bulletin at NHTSA ↗The intent of this service bulletin is to identify aftermarket ALDL or DLC interface devices as potential sources for causing multiple customer concerns that do not have other diagnostic methods to identify them.
full bulletin at NHTSA ↗This service bulletin provides information for dealers/technicians on Service Programming System (SPS) Error Codes E4398, E4399, E4401, E4403, M4404, M4413, M6954, M6955, E4414, E4423, E4491, E4492, or E6961 and resolution information.
full bulletin at NHTSA ↗This service bulletin provides repair information to correct a customer concern of Vehicle Will Lock and Unlock (Active Functions Work) but Will Not Crank or Start (Loss of Passive Functions Do Not Work).
full bulletin at NHTSA ↗Source: NHTSA manufacturer communications. Bring the bulletin number to your dealer or shop.
What owners are reporting 3 most recent
I dropped my son off at school and he mistakenly took my car keys into school with him, and somehow I was able to drive all the way home, 4.5 miles, with no key in the car and no warning to stating the remote wasn't in the car. The issue with this is if I'd driven further, perhaps to another state, or even driven somewhere at night, I would have been stranded once I turned the car off. There was…
Recently I have noticed that the back brakes squeak and sound like they are grinding when backing up. Also every now and then the information screen will go black for a while then turn back on could be a few seconds or several minutes. 23,900 on car
Driving my vehicle with no warnings, messages, or symptoms on adaptive cruise control Sunday [XXX] on [XXX] in Michigan. I changed lanes into the right lane when the vehicle abruptly, without notification, and with force, caused braking that unexpectedly and dangerously slowed the vehicle then released braking before doing the same a moment later. Vehicle was pulled off the road onto the…
Had electrical trouble with your 2021 GMC Terrain?
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 GMC Terrain?
It's a documented issue but not catastrophic. 5 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?
Mileage data is limited for this issue. Owners report failures across a wide range, suggesting cause is more about driving conditions and maintenance than mileage alone.
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/GMC/Terrain.
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.