NHTSA Investigation
RQ17002
Loss of Headlights
Key Takeaways
- Investigation RQ17002 currently maps to 9 tracked vehicle-year pages across 2 makes.
- This page summarizes the public investigation subject, status, timing, and affected tracked vehicles linked from NHTSA source data.
- The linked component on this record is exterior lighting:headlights.
What This Investigation Page Shows
This page summarizes a public NHTSA investigation record tied to one or more tracked vehicle-year pages in our database. Investigation records sit between owner complaints and recall campaigns: they can remain open, close without a recall, or connect to a later remedy action. Use this page to see which tracked vehicles are linked to the record, then open the individual vehicle pages for complaints, recalls, and crash test context.
Investigation Summary
The subject vehicles are model year (MY) 2002-2009 Chevrolet Trailblazer, GMC Envoy, 2004-2007 Buick Rainier, 2003-2008 Isuzu Ascender, 2005-2009 Saab 9-7X, 2002-2004 Oldsmobile Bravada, 2003-2006 Chevrolet SSR, 2005-2009 Buick Lacrosse, and 2006-2008 Pontiac Grand Prix. This scope includes the Trailblazer/Envoy variants: 2002-2006 Envoy XL/Trailblazer EXT and 2004-2005 Envoy XUV. The original scope of this investigation was expanded to include all vehicles equipped with the subject Headlight Driver Module (HDM). The focus of the investigation was to determine whether actions performed by General Motors adequately addressed any unreasonable risk to motor vehicle safety in the subject vehicles concerning the headlights and the HDM that controls them.Under normal electrical load and environmental conditions, the HDM can overheat inside the Underhood Electrical Center (UEC). This can cause the module to fail and result in a simultaneous loss of both low beam headlights and both daytime running lights (DRLs), often with no warning or prior detectability to the driver. This failure can be intermittent or permanent. No other exterior lights are affected. High beams, turn signals, brake lights, and reverse lights are still operational.General Motors addressed this issue with 2 recalls (14V755 & 15V519) and a special coverage program (N172091910). In view of the recalls and special coverage program implemented by GM and the vehicle high beams continuing to operate, ODI has tentatively concluded that the actions taken by GM mitigate any unreasonable risk to safety posed by HDM failure in the subject vehicles.Accordingly, the investigation is closed. The closing of this investigation does not constitute a finding by NHTSA that a safety-related defect does not exist. The agency reserves the right to take additional action if warranted by new circumstances.The ODI reports cited above are available for review online at NHTSA.gov under the identification numbers in the attached document.
Manufacturer listed on the source record: Isuzu Motors Limited
Component listed on the source record: EXTERIOR LIGHTING:HEADLIGHTS
Affected Vehicles (9)
Browse Affected Vehicles
Affected Makes
Affected Models
All data is sourced from NHTSA public records. This site is not affiliated with, endorsed by, or operated by the National Highway Traffic Safety Administration or any government agency. Complaints are unverified consumer reports submitted to NHTSA and may not reflect confirmed defects. For official information, visit nhtsa.gov.
Data synced from NHTSA on Sep 8, 2026