2012 GMC Terrain electrical problems

Engine repeatedly shuts off when the vehicle approaches a stop, idles, comes to a red light, or accelerates. Multiple owners report the vehicle dies unexpectedly while driving at various speeds, with dashboard going black and loss of power steering and braking assist.

When: Throughout ownership; occurs at idle, stop signs, red lights, or during normal acceleration; mileage varies (50K-95K reported)

Symptoms owners cite: Engine shuts off at idle or approach to stop; Engine dies during acceleration; Center console goes completely black during stall events; Loss of electrical power during stall; Emergency brake applies automatically on some occasions; Vehicle requires jumping to restart after stall; Multiple stalls in sequence before engine runs

Codes mentioned: P0013, P0016, P0300, P0335

Repairs/costs cited: Owners report replacement of spark plugs, coolant sensor, crankshaft sensor, camshaft (both sides), and internal computer; repairs often temporary or ineffective. Dealers unable to identify root cause despite multiple visits (one owner: 7 shop visits without resolution). One case required engine replacement per dealership assessment.

Recalls/TSBs owners mention: NHTSA Campaign 22V137000 mentioned for exterior lighting; parts unavailable per VIN tool. Dealer service records indicate inability to diagnose or resolve issue in most cases. One owner reports GM slow to provide resolution after vehicle fire.

Battery dies repeatedly on weekly basis or after short periods of non-operation. Vehicle fails to start without external jump; key sometimes becomes stuck in ignition switch and will not turn.

When: Throughout ownership; battery drain occurs on weekly basis in some cases; starting failures reported between 27K–95K miles

Symptoms owners cite: Battery drains on weekly basis; Vehicle will not start without jump; Key becomes stuck in ignition switch; Ignition switch will not turn; Car locks keys into ignition; No click sound when attempting to start after battery drain; Passenger-side headlamp fails to illuminate

Codes mentioned: P0011, P0012

Repairs/costs cited: Owner replaced battery multiple times (new battery installed; replaced again within weeks in some cases). Alternator replaced in at least one case. AAA replaced battery on-site in one complaint. No permanent fix achieved in reported cases despite multiple replacement attempts.

Recalls/TSBs owners mention: NHTSA Campaign 22V137000 (Exterior Lighting) noted in one complaint; parts not available per VIN tool. No manufacturer notification or response documented in most cases.

Low beam H11 bulb connector (male/female plug) overheats, causing plastic housing to char, melt, and become brittle. Wiring insulation melts, exposing bare wire and creating fire hazard. Low beam bulb fails repeatedly on same side after replacement.

When: Occurs within 9 months of replacement; vehicle has only 28,755 miles; failure occurred multiple times (right side twice, left side once)

Symptoms owners cite: Plastic connector housing charred and partially melted; Plastic connector becomes brittle; Wiring becomes soft at plug connection; Wire insulation melted, bare wire visible; Low beam light stops working; Recurrence of failure on same side within 9 months

Repairs/costs cited: Bulbs and female plug connectors with male electrical connections replaced three times. Right side replaced within the last 9 months; failure recurred.

Dashboard display screen goes completely black, eliminating visual status of HVAC temperature control, emergency lights, and A/C control buttons. Center console becomes unresponsive. Backup camera stops working. Turn signal loses click sound. Radio/audio system loses sound completely. Interior lighting (emergency and A/C control buttons) illumination lost, creating night-driving hazard. Issue reported from 2018 onwards in one case.

When: Intermittent; occurs during driving and persists for hours; issue ongoing from 2018 onwards in one complaint; reported from purchase onwards in others

Symptoms owners cite: Dashboard and GPS/radio display screen blackout; Intermittent control button illumination loss; Emergency and A/C control lights go off; Backup camera stops working; Turn signal loses click sound; Complete audio/radio loss; Center console completely black; Dash stays black for hours then comes back on; Radio freezes at any moment; Radio will not turn off even after removing key and locking vehicle

Repairs/costs cited: One owner reports dealer offers only non-guaranteed refurbished head unit replacement at hefty price. No other repairs documented; issue remains unresolved in multiple cases. One case involved replacing internal computer; subsequent stall events still occurred.

Recalls/TSBs owners mention: Owner contacted GM with no meaningful resolution. Dealer replacement parts not guaranteed. Widespread similar complaints online identified by owner; GM has not addressed.

Stability Track, ABS, and TPMS sensor warning lights illuminate simultaneously and then clear without owner action, recurring multiple times per week. Vehicle may enter limp mode with reduced engine power when warning lights come on during driving.

When: Recurring 4+ times per week; occurs at idle and during driving

Symptoms owners cite: Stability Track warning light comes on; ABS warning light comes on; TPMS sensor warning light comes on; All three lights come on together and go away together; Engine power reduced notification; Vehicle enters limp mode; Cannot accelerate over 30 mph when limp mode engaged; Vehicle shakes and rocks at stop lights

Codes mentioned: P0335, P0600

Repairs/costs cited: Stability Track sensor replaced in one case; lights continued to cycle. One owner invested over $3,000 in parts and visits to multiple mechanics without resolution. Replacement of pedal sensor, coolant sensor attempted.

Check Engine light comes on and remains on despite multiple service attempts. Fuel cap sensor fault code triggers even after cap replacement. Emission control system fails repeatedly within short time period. Multiple fault codes appear without clear root cause.

When: Fuel cap sensor codes recur 4 times within 6 months after replacement; emission control failure twice within 3 months; check engine light on continuously from purchase in one case

Symptoms owners cite: Check Engine light illuminates and stays on; Fuel cap sensor fault code triggers repeatedly; Emission control system malfunction; Multiple different fault codes appear; Check engine light comes on and off intermittently; Vehicle would not pass inspection due to check engine light

Codes mentioned: P0440, P0441

Repairs/costs cited: Fuel cap replaced multiple times but code recurs. Camshaft (both sides) replaced. Crankshaft replaced. Mechanics unable to identify root cause. One owner replaced spark plugs, battery, alternator, and other parts totaling over $1,200 without resolution. One case involved dealership assessment that entire engine replacement needed due to multiple parts failures.

Recalls/TSBs owners mention: Multiple parts on recall per dealership inquiry in one case; owner was not notified of recalls. GM did not post recalls or contact owner.

Radio and volume freeze at random moments, requiring vehicle to be stopped and idling for extended period before radio becomes active again. Radio turns on without key in ignition, even with vehicle off and locked. Radio will not shut off even after removing key and locking vehicle.

When: Freezes occur at any given moment; occurs during driving and after parking

Symptoms owners cite: Radio freezes at any moment; Volume becomes unresponsive; Radio must idle for period of time to become responsive; Cannot change stations when frozen; Radio turns on with vehicle off; Radio will not shut off after key removal; Radio keeps running even with key removed and vehicle locked; Speaker sound becomes blown with buzzing during acceleration

Repairs/costs cited: Dealer told owner this issue seen frequently; cost quoted at $150 after warranty expiration. No repair solutions documented.

Recalls/TSBs owners mention: Dealer reports this is a known issue ('seen this issue alot') but no recall or TSB mentioned. Owner notes concern about other electrical systems potentially malfunctioning if radio stays on unpowered.

Headlamp and backup light failures. Interior lighting (dashboard, emergency, A/C buttons) goes dark. Lighting becomes abnormally dim in dark conditions but bright when sun is out, suggesting voltage regulation issue. Turn signal loses audible click alert.

When: Backup lights failed in May 2018 (one case); passenger side headlamp failed at 78K miles; interior lighting losses reported throughout ownership

Symptoms owners cite: Passenger-side headlamp fails; Backup lights stop working coincident with rear camera failure; Interior dashboard lighting goes dark; A/C control button illumination goes off; Emergency light illumination lost; Headlamp connector overheats causing charring and melting; Lighting becomes dim in darkness but bright in sunlight; Turn signal loses click sound alert

Repairs/costs cited: Headlamp connector replacement (bulb, female plug, and male electrical connection) performed multiple times but recurred within 9 months. Dealer charged $175 to disconnect malfunctioning rear camera and replace backup light connector. No permanent solution documented.

Recalls/TSBs owners mention: NHTSA Campaign 22V137000 (Exterior Lighting) exists; parts not available per VIN tool. Dealer exceeded reasonable repair time per owner.

Rear camera stops working intermittently or permanently, sometimes showing black screen or static. Camera failure is tied to backup light failure in at least one case, creating loss of critical safety feature.

When: Camera failure reported in May 2018 in one case; intermittent failures in another (works 'sometime either black or static looking')

Symptoms owners cite: Rear camera displays black screen; Rear camera displays static; Camera stops working entirely; Backup lights fail coincident with camera failure; Loss of visual backup assist

Repairs/costs cited: Dealer diagnosed camera as faulty and disconnected it; charged owner $175. No replacement documented. One owner notes frequent intermittent failures.

Passenger-side seatbelt continuously sends false warning notification that seatbelt needs to be latched, even when no one is sitting in seat and seatbelt is properly fastened or empty. Warning chimes/rings constantly.

When: Constant throughout ownership

Symptoms owners cite: Seatbelt warning chime sounds continuously; False seatbelt latch notification when seat is empty; Warning sounds even when seatbelt is properly latched; Constant ringing of seatbelt alarm

Air conditioning leaks inside vehicle on both sides during summer months. Heating does not work in winter. Defroster will not switch air flow to vent, causing continuous windshield fogging that obstructs driver view and creates safety hazard. Issue occurs constantly, especially during highway driving and rainy/humid weather.

When: Summer months (A/C failure with internal leak); winter months (heater failure); defroster issue occurs constantly during highway and side street driving in rain or humidity; reported at 27K miles

Symptoms owners cite: Air conditioning not working; A/C leaks inside vehicle on both sides; Heater does not work; Defroster will not switch air flow to vent; Windshield fogs up constantly; Windshield fogs during rain or humid weather; Continuous fogging obstructs windshield view

Repairs/costs cited: Independent mechanic could not determine nature of failure. No repairs completed. Vehicle not repaired.

Ignition switch becomes difficult to turn or completely stuck. Key becomes stuck in ignition and cannot be removed. Ignition switch fails to turn after key is inserted, preventing engine start.

When: Reported at 41K miles in one case; recurring issue when relapse occurs within days of initial repair

Symptoms owners cite: Key becomes stuck in ignition switch; Ignition switch will not turn; Vehicle will not start due to stuck ignition; Key cannot be removed from ignition; Vehicle locks keys into ignition

Repairs/costs cited: Dealer replaced ignition key in one case; failure recurred within days. No permanent fix documented.

Engine produces loud high-pitch rattle or knock sound upon startup, especially in mornings after sitting overnight. Engine sounds weak after diagnostic check. Motor knocks badly throughout startup.

When: Upon cold startup in mornings; consistent pattern

Symptoms owners cite: High-pitch rattle sound on startup; Loud knocking sound upon startup; Engine sounds weak after startup; Motor knocks badly during startup

Repairs/costs cited: Independent diagnostic check showed engine is very weak. No repairs documented.

During bad weather, windshield wipers move past normal windshield boundary and motor freezes up. Motor begins humming then locks up completely, leaving wipers stuck.

When: During bad storm

Symptoms owners cite: Wipers move past windshield boundary; Wiper motor freezes up; Motor hums then locks; Wipers become stuck in extended position

Airbags failed to deploy during front-end accident at 55+ mph speed after hitting large dip in road, despite force of impact. Seatbelts did lock but airbags did not.This may be related to the seatbelt sensor malfunction reported elsewhere.

When: During front-end accident at 55+ mph

Symptoms owners cite: Airbags did not deploy during high-speed front impact; Seatbelts locked but airbags failed

Engine consumes excessive amounts of oil, requiring frequent refilling. Oil burn occurs within 1000 miles of oil change. PVC valve issue caused rear main seal to consume oil and gasket to blow out. Engine overheating/fire risk during dealer diagnostic drive. Vehicle caught fire while being driven for diagnostic oil consumption check.

When: Continuous throughout ownership; fire occurred during dealer diagnostic drive

Symptoms owners cite: Low oil level within 1000 miles of change; Excessive oil burn; Frequent need for oil refilling; PVC valve failure; Rear main seal leak; Blown out gasket; Engine smoking and catching fire; Engine knocking and rattle sounds

Repairs/costs cited: Dealer assessed that entire engine would need replacement due to extent of problems (excessive oil consumption combined with multiple electrical and engine failures). Vehicle caught fire during dealer test drive for oil consumption determination, forcing driver to force way out. One owner had to replace spark plugs and other parts totaling over $1,200; still not fixed.

Recalls/TSBs owners mention: Dealership found multiple parts on recall when asked about the issue; GM had not notified owner of recalls. GM was slow to provide resolution after fire incident. Owner requested loaner vehicle but was told it couldn't be provided at that time.

Engine power reduced notification comes on repeatedly despite replacement of battery and alternator. Throttle goes out while driving highway speeds. Engine power feels weak and unresponsive. Vehicle enters limp mode limiting speed to 30 mph when issues occur.

When: Throughout ownership; throttle failure while driving 65 mph on highway; power reduced notifications recurring after parts replacement

Symptoms owners cite: Engine Power Reduced warning light comes on; Engine power reduced despite new battery and alternator; Throttle fails during highway driving; Unable to accelerate normally; Vehicle enters limp mode; Maximum speed limited to 30 mph; Weak engine power

Codes mentioned: P0101, P0335, P0500, P0600

Repairs/costs cited: Battery and alternator replaced; issue persists. Multiple mechanics unable to identify cause. One owner invested over $3,000 in repairs without resolution.

Driver seat will not move forward or backward. Driver side visor will not stay up. Multiple mechanical and electrical control failures in quick succession.

When: Within 5 years of ownership

Symptoms owners cite: Driver seat will not move forward; Driver seat will not move backward; Driver side visor will not stay up