Owner was driving and vcs and ABS warning lights came on and stayed on while driving as well as tire pressure light. Brakes on vehicle did not brake as well going down hill. Tires slipped and skidded in the rain on the hills in ventura county. Driver called Toyota and they opened up a case number. Toyota has attempted to fix the vehicle 3 times and cannot determine the reason why the…
2012 Toyota Sienna electrical problems
severe 24 complaints filed with NHTSA · avg repair $850 · see electrical across all vehicles →
Failure mileage
Complaints
24
Recalls
0
Avg fix
$850
2fires
When does it fail?
Of the 24 electrical complaints filed for the 2012 Toyota Sienna, 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
No new NHTSA electrical complaint has been filed on this vehicle in over 13 years — the issue may be aging out of the active population.
The failure pattern owners describe
Buyer takeaway: A used 2012 Sienna electrical problems cluster includes recurring alternator failure with stalling, complete power loss, engine fire from harness failure, power sliding door latch/motor defects that open while driving, ABS/VSC warning lights with brake issues, and dashboard/sunroof electrical failures. Multiple repairs often fail to resolve intermittent faults, and some issues (door latches, cable snaps) remain outside official recalls despite known hazards.
Owners report a pattern of serious electrical and power-system failures. The most recurring complaint is power sliding doors that fail to latch or close, opening unexpectedly while driving with children aboard—some owners must bungee doors shut to drive 30 miles home. Door motors and latches fail frequently, costing $1,200–$2,100 out of pocket; one repair note states this is "incredibly common" but Toyota has resisted remedies. Cables snap on their own, trapping children inside.
Dashboard and charging failures are widespread. Some vans lose all electrical power at startup or while driving, with no door locks, radio, or lights for several minutes. Others show battery warning lights followed by stalling; alternators replaced twice still don't fix it. Two vehicles caught fire due to electrical surges in the harness behind the battery.
ABS and VSC warning lights stay on while braking performance drops, causing tire slip on wet hills. Speedometers become erratic or frozen, and fuel gauges stick on full. Dashboard instruments won't illuminate during daylight or cloudy weather, making them unreadable.
Sunroofs stick open, intermittent wipers run backwards, and dealers often cannot diagnose these problems or claim no fixes exist. Owners cite frustration with Toyota's slow response and denial of warranty coverage for known defects.
Same Toyota Sienna electrical reports on nearby years: 2010 · 2011 · 2013 · 2014 · 2015
Failure modes owners describe
Alternator failure with battery warning light
Battery warning light illuminates on dashboard, often followed by stalling. Multiple alternator replacements fail to resolve the intermittent issue. Dealer unable to diagnose root cause on third visit despite customer video evidence.
When: November 2013 onwards; Nov 2013, Jan 2014, Mar 2014 visits documented
Symptoms owners cite: Battery light illuminates on dashboard; Vehicle stalls while driving; Intermittent warning light recurrence despite repairs
Repairs/costs cited: Alternator replaced twice (Nov 2013, Jan 2014) with no permanent resolution
Recalls/TSBs owners mention: Toyota denied lemon law claim stating vehicle conformed to warranty within reasonable opportunities
Complete electrical system shutdown
Vehicle loses all electrical power during operation or at startup—no door locks, radio, lights, or engine function. Power returns after 5+ minutes. Dashboard electronics reset after power restoration. Occurs intermittently over span of one year.
When: February 4, 2015 (second occurrence that week); prior incident approximately one year before (around Feb 2014)
Symptoms owners cite: Total loss of electrical power; No door locks, radio, or lights functional; Navigation DVD resets; Vehicle becomes unable to start until power spontaneously returns
Repairs/costs cited: Battery tested in good condition; dealer unable to help
Electrical fire in engine harness
Electrical surge causes dashboard lights to flash and engine to stall at stop lights. Fire ignites in wrapped wires behind battery; entire electrical harness requires replacement. Vehicle has under 65,000 miles and recent 60K service.
When: Approximately 6 months after 60K maintenance (60K service performed June 2018)
Symptoms owners cite: Electrical surge at stop lights; Dashboard lights flash; Engine shuts off; Smoke from under hood; Fire in wired harness behind battery
Repairs/costs cited: Entire electrical harness and nearby parts require replacement; minimal engine damage contained
Power sliding door latch and motor failures
Power sliding doors (one or both) fail to latch or close properly, requiring manual force or becoming stuck open. Doors open spontaneously while driving at highway speeds with children aboard. Door motors and latches fail; cable snaps or frays. Doors must be manually held closed or bungeed shut.
When: Varies; recalls issued January 2017 and earlier; failures reported through 2017-2018
Symptoms owners cite: Door fails to latch or close automatically; Door opens spontaneously while driving; Door can only be closed manually with great force; Door cable snaps or frays; Rear latch stuck in lock position; Door motor whines during closing cycle
Repairs/costs cited: Replacement cost cited $1,200–$2,100 for motor and latch repairs; some dealers place door on manual mode; cable replacement inadequate if latch also faulty
Recalls/TSBs owners mention: Recall issued for door cables but not latches; manufacturer stated 'no remedy yet' in January 2017 recall letter; some coverage for out-of-warranty splits (50/50)
ABS and VSC warning lights with brake system malfunction
ABS, VSC, and brake warning lights illuminate and remain on while driving. Speedometer and fuel gauge become inoperative or erratic. Brake performance compromised, particularly on downhill grades. Lights triggered by cold weather (45°F) in one documented case.
When: October 5, 2014 (after temperature drop to 45°F); ongoing across multiple vehicles
Symptoms owners cite: ABS warning light on; VSC (Vehicle Stability Control) warning light on; Brake system warning light on; Speedometer needle moves back and forth or non-responsive; Fuel gauge stuck on full; Brake warning indicator stuck on; Reduced braking performance on hills; Tire slipping and skidding in wet conditions
Codes mentioned: ABS malfunction, VSC malfunction, Brake system fault
Repairs/costs cited: Dealer unable to determine cause after 3 repair attempts
Dashboard illumination failure
Dashboard does not illuminate properly during daytime driving or in low-light conditions. Instruments remain dark or barely visible even with headlights on. Gray dashboard color blends with insufficient lighting during cloudy weather.
When: Intermittent; affects multiple 2012 Siennas
Symptoms owners cite: Dashboard does not illuminate during daytime with daytime running lights on; Poor illumination even with headlights on; Instruments difficult to read on cloudy days; Dashboard illumination only comes on when light switch is activated
Sunroof stuck open
Sunroof becomes stuck in open position and will not close whether vehicle is moving or stationary. Reported in conjunction with power door latch failures.
When: Timing not specified; reported as secondary to door issues
Symptoms owners cite: Sunroof stuck in open position; Sunroof will not close while driving; Sunroof will not close while stationary
Intermittent wiper speed reversal
Intermittent wiper function operates in reverse—slow setting runs fast, fast setting runs slow. Dealer unable to correct.
Symptoms owners cite: Slow wiper speed setting operates at fast speed; Fast wiper speed setting operates at slow speed
Repairs/costs cited: Dealer advises no repair possible
Engine stall with loss of power steering
Engine stalls unexpectedly while driving, causing power steering to freeze. Occurs repeatedly even after battery replacement. Defect undiagnosed.
Symptoms owners cite: Engine stalls during driving; Power steering becomes frozen; Stalling repeats after battery replacement
Repairs/costs cited: Battery replaced but stalling continues
Synthesized from 24 NHTSA owner complaints — unverified consumer allegations, summarized for patterns. The verbatim filings appear below.
What owners are reporting 3 most recent
No dashboard lights when van is started, only come on when light switch is activated. Dashboard on visible on cloudy days. *tr
Was driving home from running errands, about a 4 mile drive at 35 miles/hr. At a stop light there seemed to be some sort of electrical surge. All the dashboard lights flashed and the vehicle turned off. I was able to put the car in park and restart it. There were no warning lights on after restarting the engine, so I assumed it was a fluke and continued on my way home. A little further down…
Had electrical trouble with your 2012 Toyota Sienna?
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 2012 Toyota Sienna?
It's a meaningful issue. 24 complaints have been filed and the failure mode causes operational problems for owners. Repairs average $850.
At what mileage does the electrical typically fail?
Across the 13 complaints that reported odometer mileage, most electrical failures cluster between 30,000 and 70,000 miles, with the median around 46,250. A quarter of owners report trouble before 30,000; a quarter make it past 70,000. Maintenance history matters more than the odometer alone — this is the reported failure window, not a guarantee.
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/2012/Toyota/Sienna.
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.