Failure modes owners describe
Intermittent power reduction / limp mode with Code 84
Vehicle enters power reduction mode unpredictably while driving, limiting acceleration and creating a safety hazard on highways. Check Engine light and StabiliTrak indicator illuminate intermittently. Diagnostic scans show no fault even when symptoms occur. Multiple pedal assembly replacements have not resolved the issue. Mechanics suspect electrical root cause but cannot locate source.
When: After 1 year of ownership; occurs daily for extended periods; happens at any speed but reported on highway and during normal driving
Symptoms owners cite: Power reduction mode activation; Reduced acceleration capability; Check Engine light illumination (intermittent); StabiliTrak warning light; Code 84 recorded
Codes mentioned: Code 84
Repairs/costs cited: Pedal assembly replaced twice at Midas with no lasting resolution; mechanics report unable to identify electrical source despite diagnostics
Gauge cluster display failure—odometer and trip meter show dashes
Odometer and trip meter display only three dashes instead of mileage numbers. Battery disconnect or fuse pull temporarily restores display for seconds before reverting to dashes. Affects vehicle's ability to track maintenance intervals and report accurate mileage for insurance. Dealership diagnostic fee quoted at $700 nonrefundable deposit plus additional parts and labor. Issue occurs out of warranty.
When: Around 38,000–45,600 miles on affected vehicles; persists for months after occurrence
Symptoms owners cite: Odometer displays only '---'; Trip meter displays only '---'; Temporary restoration of display after battery disconnect or fuse pull; Inability to reset trip meter
Repairs/costs cited: Dealership quotes $700 diagnostic deposit nonrefundable; owners report unable to repair at independent shops due to computer nature; issue remains unrepaired
Gauge cluster malfunction—rapid speed and RPM fluctuation, turn signals fail
Gauge panel displays erratic speed and RPM readings that fluctuate rapidly and inaccurately while driving. Turn signals stop functioning during episodes, creating a safety issue. TractionControl light illuminates, suggesting system shutdown. Problem is intermittent and cannot be reproduced during dealer diagnostic attempts, leaving vehicle unrepaired.
When: During motion; reported at 60 MPH; intermittent occurrence; vehicle is under warranty at time of report
Symptoms owners cite: Speed gauge fluctuates rapidly and inaccurately; RPM gauge fluctuates rapidly and inaccurately; Turn signals become inoperative; TractionControl light illuminates
Repairs/costs cited: Dealer unable to reproduce problem during diagnostic; vehicle returned without repair
Rear window defrost electrical failure with glass implosion
Rear windshield suddenly imploded while vehicle was moving at low speed, propelling glass shards into cabin and injuring driver's eye. Abnormal electrical humming sound preceded failure. Melted solder found at rear window defroster electrical connection. Prior electrical shortage failures reported on vehicle. Manufacturer field investigator unable to determine cause.
When: At 125,000 miles; during low-speed driving (15 MPH); on a regular road
Symptoms owners cite: Abnormal electrical humming sound from rear windshield; Sudden rear windshield implosion; Glass shards propelled into cabin; Melted solder at defroster electrical connection
Repairs/costs cited: Vehicle not diagnosed or repaired; field investigator inspection did not determine cause; police report filed; owner sustained eye injury requiring medical attention
Console and directional lighting electrical shutdown in cold weather
Entire middle console loses power and directional lights fail to activate during winter months. Only temporary workaround is repeated pushing of rear window defrost button. Directional wand has been replaced and two manufacturer recalls addressed, but failures persist every winter.
When: Winter season, recurring annually since winter 2012
Symptoms owners cite: Middle console complete power loss; Directional lights fail to activate; Temporary recovery possible only by repeated rear defrost button activation
Repairs/costs cited: Directional wand replaced; two manufacturer recalls addressed without resolving issue
Recalls/TSBs owners mention: Two recalls addressed but failures persist
MyLink stereo system malfunction—uncontrolled operation and random function activation
MyLink stereo changes stations randomly and constantly, reprogrammed all stations to same channel, touch screen becomes unresponsive. Bluetooth hands-free disconnects automatically due to random calling. Stereo has called 911 without owner activation. System operates erratically whether vehicle is parked or in motion. Multiple owners report identical issue on social media.
When: Reported starting in April 2015 in one case; occurs at any time parked or driving
Symptoms owners cite: Radio stations change on their own; All stations reprogrammed to single channel; Touch screen unresponsive to input; Bluetooth randomly calls people from recent call list; System called 911 without user activation; Radio plays while car is parked and off; XM subscription unusable
Repairs/costs cited: Multiple owners affected report problem in Facebook group (10–15 people identified); no repair attempts documented in narratives
Key fob combination—unintended ignition shutdown from accidental contact
Key fob physically attached to key with solid design allows accidental activation when bumped during normal use. Owner struck fob while reaching for wiper control, causing key to turn in ignition and shut off engine while driving. Similar issue reported in other GM vehicles and resolved by separating key from fob.
When: During normal operation; while reaching to activate wipers
Symptoms owners cite: Accidental key rotation when fob struck; Engine shutdown without driver intent; Risk of steering wheel lock if incident occurs at speed
Repairs/costs cited: No repair documented; owner recommends separating key from fob to prevent recurrence
Door lock electrical malfunction—doors unable to unlock or lock properly
Driver side door exhibits double-locking mechanism where door locks immediately upon opening attempt after being parked. Door lock solenoid fails to fully engage, leaving doors completely unable to open. Key fob command to unlock results in lock cycling up then immediately back down. Doors cannot be opened from outside when lock fails. Multiple repair shops unable to diagnose root cause. Creates serious safety hazard in case of accident.
When: Intermittent; one incident required multiple attempts to open passenger door while driver door remained completely locked
Symptoms owners cite: Driver side door locks during opening attempt; Door lock solenoid cycles up then down without remaining unlocked; Doors unable to open from outside when malfunction occurs; Key fob unlock command ineffective
Repairs/costs cited: Multiple repair shops unable to diagnose; no repair successful
Door lock electrical shortages—inability to unlock doors, lockout situations
Doors fail to remain unlocked when exiting vehicle, and doors fail to unlock when commanded. Owner became locked out for hours; independent mechanic diagnosed failing door sensor with electrical shortage. Door sensor replacement performed at dealer.
When: At 44,000 miles
Symptoms owners cite: Doors fail to unlock when commanded; Owner locked out of vehicle for extended period; Multiple unlock attempts required to finally open doors
Repairs/costs cited: Door sensor replaced at dealer; failing door sensor with electrical shortage was root cause
Key stuck in ignition—unable to remove key after engine off
Ignition key becomes stuck and cannot be removed after engine shutdown. Issue has occurred multiple times and is now happening daily. Owner has videoed failure to show dealership. Gear shift console housing cleaning and shifter cable degreasing provide only temporary relief; failure recurs within one week.
When: First occurred after October 2013 purchase; now occurring daily; one instance required 15 attempts to start before key would turn
Symptoms owners cite: Key will not turn in ignition to start; Key stuck and cannot be removed from ignition; Key requires multiple insertion/removal cycles before starting
Repairs/costs cited: Gear shift console housing cleaned internally and shifter cable cleaned with degreaser at dealer; temporary relief only, failure recurred within week
Engine won't turn off—key removed but engine continues running
Key removed from ignition but engine fails to shut off. Vehicle also loses ability to accelerate beyond 5 MPH. All power windows become inoperative simultaneously. Indicates broad electrical system failure or wiring issue.
When: At approximately 69,896 miles
Symptoms owners cite: Engine continues running after key removed from ignition; Vehicle will not accelerate beyond 5 MPH; All power windows inoperative
Repairs/costs cited: Wiring in vehicle repaired at Power Chevrolet dealer
Recalls/TSBs owners mention: Manufacturer notified and provided case numbers 8-4486719908 and 8-4102065156
Radio and electrical system failures—battery drain from random activation
Radio turns on by itself while vehicle is parked and engine is off, draining battery. Occurs at least three times with third occurrence killing the battery. Radio was powered off before car was turned off. Happens regardless of whether vehicle is in motion or parked.
When: Starting April 2015 and continuing; third occurrence drained battery completely
Symptoms owners cite: Radio powers on while parked and engine off; Radio audible from outside vehicle next morning; Battery drain results in dead battery
Repairs/costs cited: No repair documented in narrative
Turn signal and wiper switch electrical failure
Window wiper and washer switch fails during low-speed driving. Anti-theft warning indicator illuminates during failure. Switch replacement performed at independent mechanic but failure persists after repair.
When: At 38,000 miles; while driving 20 MPH
Symptoms owners cite: Window wiper/washer switch fails; Anti-theft warning indicator illuminates
Repairs/costs cited: Window wiper/washer switch replaced at independent mechanic; failure recurred after repair
Wiper pump electrical failure—no washer spray function
Windshield wiper pump fails to spray washer fluid when activated.
When: <UNKNOWN>
Symptoms owners cite: Windshield wiper pump will not spray washer fluid
Ignition warning chime failure—no audible alert when key left in ignition
Chime fails to sound when key is placed in ignition or left in ignition after engine shutdown. Related to MyLink radio system failures. Recall 17130 was closed on vehicle according to GM, but chime still inoperative. Issue affects compliance with federal theft protection standard.
When: Present at vehicle purchase (94,000 miles); recurring issue since recall closure reported for 2013–2016 model years
Symptoms owners cite: No audible warning chime when key left in ignition; Related to MyLink system malfunction; Doors fail to remain unlocked on exit
Repairs/costs cited: Vehicle not diagnosed or repaired at dealer due to diagnostic and repair fees
Recalls/TSBs owners mention: GM Recall 17130 closed on vehicle, but chime failure persists; issue affects FMVSS 114 compliance
Electrical wiring harness damage from rodent chewing
Wiring harnesses chewed by rodents twice in less than 10 days due to soy-based plastic coating. First chewing caused complete vehicle stall in traffic due to broken wires. Second incident occurred shortly after. Vehicle manufacturing uses soy-based products in wiring harness insulation, making them attractive to rodents.
When: Two separate incidents within 10 days
Symptoms owners cite: Rodent damage to wiring harness insulation; Complete vehicle stall from broken wires; Wiring harness damage detected at dealership after stall
Repairs/costs cited: Damage found and diagnosed at dealership after stall event; soy-based plastic insulation identified as cause of rodent attraction
Gear shifter button sticks—prevents proper shifting and ignition shutdown
Gear shift button becomes stuck and fails to properly lock shifter into position. Prevents engine from shutting off completely and key from being removed from ignition. Also contributes to hesitant and bad acceleration. Owner accidentally bumped shifter and car shifted into manual while driving, creating safety hazard.
When: Reported within one month of purchase
Symptoms owners cite: Gear shifter button sticks when pressed; Shifter unable to lock into proper position; Engine unable to fully shut off; Key cannot be removed from ignition; Unintended gear shifts possible from light contact
Repairs/costs cited: Owner reports problem persists; no repair documented
Power steering electrical failure—intermittent loss of assist
Power steering cuts out intermittently during driving. Tapping battery post connectors restarts power steering function, indicating electrical connection issue. Warning light may or may not illuminate when failure occurs. Daughter experienced power steering failure during curve navigation, nearly losing vehicle control.
When: Intermittent; occurred during curve navigation at unknown speed
Symptoms owners cite: Complete loss of power steering assist; Power steering restarts after battery post connector contact; Warning light may or may not illuminate; Intermittent nature makes prediction impossible
Repairs/costs cited: Temporary restart by tapping battery connectors; owner notes same mechanic states issue is common in Sonics and should be recalled
Electrical system stall with dashboard blackout
Vehicle suddenly loses all power and stalls while driving at highway speed. Dashboard goes completely blank. Engine restarts normally after pullover. Gas gauge shows incorrect reading (1 bar and 40 miles per tank when half-tank was present). Gauge gradually corrects itself as driving continues.
When: While driving home from work at 55 MPH
Symptoms owners cite: Complete vehicle power loss and stall; Dashboard blackout; Gas gauge malfunction with incorrect reading display; Miles-per-tank display incorrect
Repairs/costs cited: No repair documented; vehicle restarted without intervention
Turn signal and radio electrical failure during high-speed driving
Vehicle stalls without warning while attempting to activate turn signals at highway speed. Entire electrical system requires replacement according to independent mechanic diagnosis. Failure recurred several times.
When: While driving 70 MPH; failure recurred multiple times
Symptoms owners cite: Vehicle stalls when turn signal activated; Stall occurs without warning; Recurring nature of failure
Repairs/costs cited: Independent mechanic diagnosed entire electrical system replacement needed; vehicle not repaired
Radio and turn indicator inoperative—battery drain
Radio and audible turn indicator fail to operate when activated. Battery becomes inoperable as result. Owner references NHTSA campaign 12V454000 for electrical system and exterior lighting.
When: At approximately 67,000 miles
Symptoms owners cite: Radio fails to operate; Audible turn indicator fails to operate; Battery becomes inoperable
Repairs/costs cited: Vehicle not diagnosed or repaired
Recalls/TSBs owners mention: Manufacturer notified; NHTSA campaign 12V454000 referenced by owner for electrical system/exterior lighting
Safety feature inoperability—all instrument panel safety features fail
All safety features displayed on instrument panel become inoperable. Both turn signals fail to operate simultaneously. Creates multiple safety hazards for driver.
When: At 60,000 miles
Symptoms owners cite: All safety features on instrument panel inoperable; Both turn signals inoperative
Repairs/costs cited: Vehicle not diagnosed or repaired at dealer
Recalls/TSBs owners mention: Manufacturer notified of failure
Radio and lights electrical failures with intermittent operation
Radio goes dark intermittently and becomes nonfunctional. Power windows stop working. Headlights turn off intermittently. Multiple mechanics unable to diagnose issue until informed by one mechanic that certain Sonics have a recall with identical symptoms.
When: Problem occurring with increasing frequency; started intermittently but now very frequent
Symptoms owners cite: Radio goes dark and stops working; Power windows stop functioning; Headlights turn off intermittently; Problem frequency increasing over time
Repairs/costs cited: Multiple mechanics unable to identify cause until recall was mentioned
Recalls/TSBs owners mention: Recall exists for certain Sonics with identical symptoms
Key fob pocket activation—unintended door and trunk actuation
Key fob buttons activate unintentionally when key is placed in pants pocket. Pressing buttons are not recessed and activate easily from leg contact. Doors lock/unlock and trunk releases without owner activation. Owner worried remote start feature could accidentally start car while in pocket, creating carbon monoxide hazard in garage.
When: Recurring; happens when key in pocket during sitting or walking downstairs
Symptoms owners cite: Doors lock/unlock unintentionally; Trunk latch releases unintentionally; Buttons activate from light leg contact
Repairs/costs cited: Owner reports Ford key fob design has recessed buttons and does not have this problem
Engine stall and hesitant acceleration—post-accident electrical issues
After vehicle was repaired from collision, check engine light came on and stayed on. Vehicle shakes for 2–3 minutes while driving or while stopped. TractionControl light comes on and off intermittently. Acceleration slow or unresponsive. RPM gauge revs unprompted. Vehicle stalled while driving through city street. Engine restart without issue.
When: Following collision repair; shaking and stalling occur at any time
Symptoms owners cite: Check engine light on continuously; Vehicle shaking for 2–3 minutes while driving or stopped; TractionControl light comes on and off; Slow or unresponsive acceleration; Unprompted RPM gauge revving; Engine stalling during city driving
Repairs/costs cited: No repair documented; owner not aware of recalls
Emission codes and component replacement failures—recurring faults
Emission diagnostic codes P0171 and P0420 recur repeatedly despite component replacement. Owner replaced thermostat, catalytic converter, both O2 sensors, and exhaust hose, but codes return within days to one week. Also developed gear shifter button sticking that prevents complete engine shutdown and key removal.
When: Recurring issue persisting after multiple component replacements
Symptoms owners cite: Code P0171 recurs after replacement of components; Code P0420 recurs after replacement of components; Codes return within days to one week after repair
Codes mentioned: P0171, P0420
Repairs/costs cited: Replaced thermostat, catalytic converter, both O2 sensors, and exhaust hose; codes recurred; gear shifter button sticking also developed
Engine stall without warning—intermittent failure
Vehicle stalls several times without warning. Engine restarts successfully but failure recurs intermittently. Related to manufacturer recall regarding catalytic converter.
When: At 83,000 miles; intermittent stalling
Symptoms owners cite: Engine stalls without warning; Stall recurs intermittently; Engine restarts without difficulty
Repairs/costs cited: Manufacturer recall regarding catalytic converter was identified during inspection
Recalls/TSBs owners mention: Manufacturer notified; recall exists regarding catalytic converter
Air bag non-deployment in collision
Vehicle was struck on front driver's side by another vehicle. Air bags failed to deploy on impact despite moderate-to-severe collision. Occupants sustained whiplash and injuries. Front passenger flew into windshield. Gear shifter fractured on impact. Vehicle totaled.
When: At 57,700 miles during collision event
Symptoms owners cite: Air bags failed to deploy on front driver's side collision; Key unable to be removed from ignition after crash
Repairs/costs cited: Vehicle totaled; no repair attempted
Recalls/TSBs owners mention: Manufacturer investigated failure
Acceleration hesitation and inconsistency—shifting issues
Acceleration is consistently poor and hesitant. Shifting gears causes shifter button to stick. Owner accidentally bumped shifter and car shifted into manual while driving, creating safety hazard. Acceleration on interstate is so slow other drivers pass due to sluggish response time.
When: Within one month of purchase
Symptoms owners cite: Poor and inconsistent acceleration; Delayed acceleration response; Shifter button sticks during gear changes; Unintended gear shifts from light contact
Repairs/costs cited: No repairs documented; owner states this is last GM vehicle purchase
Vehicle smoking during normal operation
Vehicle began smoking while driving home in 86-degree weather with windows down and air conditioner off. Check engine light stays on continuously. Remote start feature stopped working. Driver side door became loose from normal opening and closing. Plastic cap on shift knob popped off.
When: After 4 months of ownership; smoking incident during normal drive
Symptoms owners cite: Vehicle smoking during operation; Check engine light continuously illuminated; Remote start non-functional; Driver side door loose; Shift knob plastic cap detached
Repairs/costs cited: Owner scheduled shop visit and considering selling vehicle
Window regulator failure—driver side window stuck
Driver side window stopped working three times. Window regulator switch fails intermittently. Shop technician can raise window using diagnostic computer, but owner cannot operate window from driver's switch.
When: Intermittent failures; three separate instances
Symptoms owners cite: Driver side window will not lower from switch; Window control switch intermittently non-responsive; Manual computer reset can temporarily restore function
Repairs/costs cited: Shop technician able to raise window via diagnostic computer; switch remains defective from driver's position
Gauge cluster total failure after collision—multiple electrical systems affected
After collision repair, child locks stopped working. Vehicle losing speed and power. Fuel economy gauge displays nonsensical numbers. Multiple electrical failures occurred simultaneously post-accident.
When: Following April 2016 collision with dump truck and subsequent repair
Symptoms owners cite: Child locks non-functional; Vehicle losing speed and power unexpectedly; Fuel economy gauge showing incorrect wild numbers; Multiple simultaneous electrical failures
Repairs/costs cited: Owner needs all systems fixed; no repairs documented
Air conditioning system electrical failures
Air conditioning compressor fuse and relays replaced but system still non-functional. Compressor will not operate. Unplugging and reconnecting compressor provides temporary one-time operation only. System does not respond to repeated reset attempts. Multiple owners report identical issues.
When: May 28, 2018 in one case; other owners report recent failures
Symptoms owners cite: Air conditioning will not blow cold air; blows hot air instead; Compressor fuse blown; Compressor relays failed; Compressor non-responsive after reset attempts; One temporary operation after manual reset then permanent failure
Repairs/costs cited: Air compressor fuse and relays replaced; $900 compressor replacement performed; all electrical issues per technician; owner spent $900 on new compressor
Radio power loss and turn signal electrical failure during acceleration
When car is turned on and put in drive, radio turns off and will not turn back on. Turn signals stop working simultaneously. Multiple ignition on/off cycles required to restore signal light function. Radio remains inoperative.
When: Recurring; occurs when accelerating from stop
Symptoms owners cite: Radio turns off when shifting to drive; Radio will not turn back on; Turn signals stop working simultaneously; Signals require multiple restart cycles to restore
Repairs/costs cited: No repair documented
Code 84 power reduction with moisture intrusion—rain-related failure
Vehicle cuts power and decelerates when driving in heavy rain. Code 84 appears with diagnostic code P2138. Known issue of rain water entering connector causing malfunction.
When: During heavy rain driving conditions
Symptoms owners cite: Power reduction/deceleration during rain; Code 84 displayed; Code P2138 displayed
Codes mentioned: Code 84, P2138
Repairs/costs cited: Owner identifies as known issue with rain moisture intrusion into electrical connectors
Unintended engine restart in park position
Engine attempts to start on its own while vehicle is parked in park position with key in ignition. Owner jiggled key to stop restart attempts. Unable to duplicate symptoms on subsequent attempts.
When: After turning off engine and exiting vehicle
Symptoms owners cite: Engine cranks and tries to start without key operation; Occurs when key in ignition and car in park
Repairs/costs cited: Owner unable to duplicate symptoms for diagnosis
Synthesized from 44 NHTSA owner complaints — unverified consumer
allegations, summarized for patterns. The verbatim filings appear below.