Owners of 2006 Envoys describe intermittent low-beam headlight failures that occur randomly while driving at any speed or even when parked. Lights cut out without warning, then self-correct after the engine is restarted or a cool-down period passes. Owners report the switch registers the lights as on even when they're off, forcing them to use high beams as a workaround. Multiple complaints reference NHTSA campaigns 14V755000 and 15V519000, which address exterior lighting defects; however, parts for campaign 14V755000 remained unavailable for extended periods, leaving owners with vehicles ineligible for repair or stuck waiting. At least one owner reports the problem recurred after the recall repair was performed.
Separate reports describe headlight beams projecting upward instead of down the road—visible as harsh reflections off the windshield in wet or foggy weather and lighting up garage ceilings when parked. The manufacturer dismissed this as normal, though the owner had never experienced it in previous GMCs.
A few complaints cite electrical issues: dimming and flickering lights, turn-signal and tail-light failures, reverse-light socket corrosion, and in two cases, melted fuse panels or wiring harnesses. One owner's bracket holding the rear third brake light broke, creating a detachment hazard. Repair attempts by dealers and independent mechanics often fail to resolve the core problem permanently.
Failure modes owners describe
Low-beam headlight intermittent failure
Low-beam headlights fail to illuminate or cut off while driving at various speeds, then self-correct after restart or sitting idle. Owners report this occurs randomly and repeatedly, sometimes multiple times per drive. High beams typically continue to work, forcing owners to use high beams as a workaround.
When: Typically 40,000–170,000 miles; failures can occur early (36k) or late (185k) in vehicle service life.
Symptoms owners cite: Low-beam headlights cut out without warning while driving; Lights fail to illuminate when switch is activated; Intermittent failures that self-correct after restart or waiting; Owner reports switch registers lights as on when they are actually off; Failure occurs at all speeds, day or night; High beams function normally as workaround
Codes mentioned: Headlamp Driver Module (HDM) failure, Light relay fault
Repairs/costs cited: Replacement of headlamp driver module is the diagnosed remedy. Some owners report a $27 module available aftermarket; dealers charge diagnostic fees ($90+ reported). Fuse panel melting and wiring harness melting documented in at least two cases. Dimmer switch replacement attempted but did not resolve issue in one case.
Recalls/TSBs owners mention: NHTSA Campaign 14V755000 (Exterior Lighting) and Campaign 15V519000 (Exterior Lighting) issued. Campaign 14V755000 involved long delays in parts availability; dealers indicated parts unavailable for extended periods. Campaign 15V519000 offered free repair under recall. GMC declined further assistance on out-of-warranty vehicles; one service rep refused to help on a 12-year-old vehicle with 71,807 miles. At least one post-recall failure reported after HDM module replacement under campaign 15V519000, with manufacturer refusing to acknowledge the recurring problem.
Headlight beam angle defect
High-beam and fog-light beams project upward into the driver's and passenger's field of view rather than horizontally down the road. Problem is most visible in wet, foggy, or snowy conditions or when parked near a wall/garage. Owner reports this lights up the garage ceiling and reflects off the windshield, blinding the driver.
When: Apparent early in vehicle service life, reported at 15,700–15,800 miles.
Symptoms owners cite: Headlight beams reflect off windshield; High-beam and fog-light beams project upward instead of forward; Bright reflection visible on garage ceiling when vehicle is parked inside; Blinding effect in mist, snow, or fog; less noticeable in dry conditions; Distraction and hindered driving ability in wet weather
Repairs/costs cited: Dealership supplied brighter bulbs as a remedy, which did not resolve the beam-angle problem. Owner believes the exterior lights are defective, not the windshield.
Recalls/TSBs owners mention: Manufacturer stated the beam reflection was normal vehicle function. Dealer checked another truck of same model and confirmed it exhibited the same behavior, after which GM said there was no problem.
Dimming and flickering of headlights and dash lights
Headlights and instrument panel lights dim, brighten, or flicker intermittently. In one case, lights progressed to complete failure before recall repair became available.
When: Reported across service life; one owner experienced flickering prior to a 2016 recall notice.
Symptoms owners cite: Headlights and dash lights dim and brighten at random; Lights flicker (low beams, high beams, daytime running lamps); Intermittent electrical short suspected; Headlight delay function fails during these events
Codes mentioned: Intermittent electrical short, Dimmer switch fault
Repairs/costs cited: Dimmer switch replacement attempted but failure recurred. Campaign 14V755000 applies; permanent remedy was unavailable at time of complaint.
Recalls/TSBs owners mention: NHTSA Campaign 14V755000 (Exterior Lighting). Dealer unable to determine when part and permanent remedy would become available.
Turn-signal and tail-light failure
Turn signal indicator blinks abnormally fast; tail light fails when turn signal is engaged.
When: At approximately 140,000 miles.
Symptoms owners cite: Left turn signal on instrument panel blinks very fast; Tail light fails when left turn signal is engaged; Failure recurs each time turn signal is engaged
Repairs/costs cited: Vehicle not taken to dealer or repaired.
Recalls/TSBs owners mention: Manufacturer made aware of failure.
Reverse-light socket corrosion
Bulb sockets for reverse lights corrode and become unusable due to placement and lack of weather protection, reducing visibility when operating vehicle in reverse.
When: Timing not specified; affects nighttime reverse operation.
Symptoms owners cite: Reverse light sockets corroded; Reverse lights inoperable; Reduced visibility at night while in reverse
Repairs/costs cited: Socket corrosion caused by road grime exposure due to poor placement and lack of protective covering.
Third brake light bracket failure
Brackets holding rear door third brake light spoiler break, creating a safety risk of the light assembly detaching and striking another vehicle.
When: Timing not specified.
Symptoms owners cite: Brackets holding rear door brake light spoiler break
Repairs/costs cited: Owner believes this is a design fault based on conversations with junkyards and dealers. Part is dealer-supplied only; commonly requested at junkyards.
Headlights fail to turn on or remain on
Headlights do not activate or remain illuminated unexpectedly. In one case, auto light function activates but lights take approximately 5 minutes to come on. Another case reports headlights remained on while parked with engine shut off.
When: Reported at 85,000 miles and other mileages unspecified.
Symptoms owners cite: Headlights fail to come on when activated; Delayed headlight activation (approx. 5 minutes); Headlights remain on while parked with engine off
Repairs/costs cited: One complaint resulted in dealer repair at 85,000 miles.
Recalls/TSBs owners mention: Manufacturer notified in at least one case.
Synthesized from 51 NHTSA owner complaints — unverified consumer
allegations, summarized for patterns. The verbatim filings appear below.