Some 2020 – 2024 model year Highlander and Highlander Hybrid vehicles may exhibit a condition in which the air conditioner does not cool due to a leak and/or corrosion in the rear underbody air conditioner tube and accessory assembly. The anti-corrosion material has been updated to reduce the possibility of this condition.
full bulletin at NHTSA ↗2020 Toyota Highlander electrical problems
severe Owners of the 2020 Toyota Highlander have filed 14 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
14
Recalls
0
Avg fix
$850
| Model year | electrical complaints |
|---|---|
| 2016 Highlander | 14 |
| 2017 Highlander | 42 |
| 2018 Highlander | 18 |
| 2019 Highlander | 50 |
| 2020 Highlander (this page) | 14 |
| 2021 Highlander | 21 |
| 2022 Highlander | 13 |
| 2023 Highlander | 12 |
| 2024 Highlander | 6 |
1crash
1injury
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.
OBSOLETE NOTICE January 30, 2026: This bulletin is now obsolete. Please see T-SB-0001-26.
full bulletin at NHTSA ↗Some 2018 – 2024 model year Toyota vehicles equipped with a Premium Audio with Dynamic Navigation System require a Special Service Tool (SST) USB flash drive to update the map, points of interest, and system software.
full bulletin at NHTSA ↗Although the HV Floor Under Wire Harness and Rear Traction Motor Cable is covered by Toyota’s New Vehicle Limited Warranty for 3 years or 36,000 miles (whichever comes first), we at Toyota care about the customers’ ownership experience. Toyota is providing extended coverage under this Customer Support Program for repairs related to excessive corrosion to the wire harness connections at the Rear Motor Generator. Excessive corrosion can cause AM Radio Static during certain drive cycles, or the vehicle may not start.
full bulletin at NHTSA ↗The air conditioning dye injection tool kit has been developed to aid in identifying the location of air conditioning refrigerant leaks. The procedures outlined in this Service Bulletin aid in locating, inspecting, and repairing refrigerant leaks.
full bulletin at NHTSA ↗Source: NHTSA manufacturer communications. Bring the bulletin number to your dealer or shop.
The failure pattern owners describe
Owners describe a persistent electrical drain causing the vehicle to lose starting ability after 3–5 hours of sitting, with battery testing showing no faults—one dealer suggested a software update might help, but the issue persists. Multiple owners report key fob lock-and-unlock failures affecting most or all doors, with some noting the problem worsened steadily over time until locks stopped responding entirely.
The rear hatch latch mechanism fails regularly, requiring owners to use the inside button or manually close it; the hatch doesn't fully secure, leaving gaps that let in road noise and prevent the dashboard from detecting the problem. One owner paid $1,198 for repair.
Other electrical issues include a blind spot monitor that fails to detect vehicles even after dealership recalibration—one owner's wife ran another vehicle off the road while trusting the system. An ECU failure was documented with limp mode and reduced engine power (code P0300), with the owner identifying a manufacturer recall for the same fault on this model year.
A few owners report engine hesitation, stalling, and uncontrolled bucking while driving, plus loud whining noises during transmission shifts—one transmission failed at 104,000 miles, past the warranty cutoff.
Same Toyota Highlander electrical reports on nearby years: 2017 · 2018 · 2019 · 2021 · 2022
Failure modes owners describe
Battery drain and no-start condition
Vehicle will not start without a jump after 3-5 hours of sitting. Battery discharges rapidly but vehicle restarts without jumps if driven within the 3-5 hour window. Remains running once jumped. Dealer suggests software update may be needed. Battery and alternator tested okay in one case but no root cause identified.
When: Since purchase (June 2020 in one case); around 57,000 miles in another
Symptoms owners cite: Will not start without jump after 3-5 hours; Battery stays charged less than one day; Vehicle stalls while driving; Vehicle operates normally once jumped
Recalls/TSBs owners mention: Dealer advised software update may be required; no other assistance or recall information provided
Door lock system malfunction
Door locks fail to lock or unlock with key fob. In one case, doors intermittently unlock after locking with fob. In another, only driver-side door stopped responding to fob; all other doors do not lock or unlock via fob. Failures became more frequent over time until constant.
When: Approximately 11,000 miles; issues started at purchase and worsened over time
Symptoms owners cite: Doors intermittently unlock after locking; Multiple doors do not respond to fob lock/unlock commands; Failures increase in frequency over time
Recalls/TSBs owners mention: Manufacturer offered no assistance; owners referred to NHTSA Hotline
Rear hatch latch failure
Rear hatch will not close or open properly. Requires use of inside button or manual closing. Hatch does not fully latch; continues to hang up and cycle. Dashboard does not indicate hatch status. Owner reported loud hissing and road noise while driving because hatch was not fully secured. Repair cost cited as $1,198.
When: Not specified; repair cost documented
Symptoms owners cite: Rear hatch will not close unless inside button used; Hatch does not fully latch; Hatch hangs up constantly; Dashboard does not notify of hatch status; Loud hissing and road noise when hatch not secured
Repairs/costs cited: Repair cost $1,198.10
Blind Spot Monitor malfunction
Blind Spot Monitoring system not working. Dealership performed recalibration but system still fails to detect large vehicles (semi trucks). System operates intermittently. Safety concern documented: owner's wife ran another vehicle off road while trusting system.
When: Not specified
Symptoms owners cite: Blind Spot Monitor not detecting vehicles; System does not see semi trucks; System operates intermittently; Recalibration did not resolve issue
Recalls/TSBs owners mention: Dealership performed recalibration but issue persists
Engine control unit (ECU) failure
ECU system failure reported. Dealership initially attributed damage to beverage spill but owner disputes this claim. Owner identified a recall affecting the same issue on this model year. Recall details not fully disclosed in narrative.
When: Not specified
Symptoms owners cite: ECU system failure; Limp mode activation; Reduced engine power on acceleration
Codes mentioned: P0300
Recalls/TSBs owners mention: Recall identified by owner for same ECU issue on this model year
Transmission internal failure with whining noise
Vehicle developed loud whining noise on acceleration. Dealership diagnosed internal transmission failure requiring replacement. Transmission failure occurred at 104,000 miles, just beyond 100,000-mile warranty limit. Replacement transmission and labor estimated at $7,425.60 plus labor costs.
When: 104,000 miles
Symptoms owners cite: Whining noise on acceleration; Transmission internal failure detected
Repairs/costs cited: Transmission replacement cost $7,425.60 plus labor
Recalls/TSBs owners mention: Warranty coverage ended at 100,000 miles; no manufacturer assistance
Engine hesitation, stalling, and bucking
Vehicle hesitates, stalls, and bucks forward uncontrollably while driving at various speeds. Very loud whining noise occurs when shifting between Park and Drive. Owners report significant safety concern with new vehicle.
When: Not specified
Symptoms owners cite: Engine hesitation; Stalling while driving; Bucking and leaping forward uncontrollably; Loud whining noise on gear shifts
Aftermarket brake control system recall
Tekonsha Prodigy RF Electronic Brake Control (part 902501) installed by independent mechanic showed connection then disconnected ('NC' message) during use. Equipment is subject to NHTSA Campaign 20E033000 (Electrical System). Neither mechanic who sold nor installed part was aware of recall. Manufacturer did not respond to replacement request.
When: 0 miles (upon initial use)
Symptoms owners cite: Brake control shows 'C' (connected) then switches to 'NC' (not connected); Equipment fails to maintain connection during operation
Recalls/TSBs owners mention: NHTSA Campaign Number 20E033000; manufacturer did not respond to replacement request
Synthesized from 14 NHTSA owner complaints — unverified consumer allegations, summarized for patterns. The verbatim filings appear below.
What owners are reporting 1 most recent
The rear hatch door will not close or open and just sit there.And dings, you have to manually close it and open it most times and it never fully sucks up and latches fully and it doesnt notify you on the hood display of the car , so when we were driving down the road, we heard loud hissing and road noise coming from the rear and come to find out the rear hatch had never fully closed or latched…
Had electrical trouble with your 2020 Toyota Highlander?
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 2020 Toyota Highlander?
It's a meaningful issue. 14 complaints have been filed and the failure mode causes operational problems for owners. Repairs average $850.
At what mileage does the electrical typically fail?
Based on the 14 complaints filed, electrical issues most often appear around 21,449 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/2020/Toyota/Highlander.
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.