The problem: in affected trucks, the 6.6L L5P V8 Duramax diesel engine may have a damaged nitrogen oxide sensor connector wire.
The hazards: a nitrogen oxide sensor is used to monitor the level of nitrogen oxide being emitted by a diesel vehicle to ensure compliance with state and federal emissions regulations. A damaged or faulty nitrogen oxide sensor can cause the vehicle to produce fault codes and can also result in a warning light illuminating on the instrument cluster. GM did not say what kind of issues owners of vehicles affected by this particular problem can expect, however.
The fix: dealers are instructed to replace the ‘Position 2’ nitrogen oxide sensor in affected vehicles. These repairs will be done at no cost to the vehicle owner.
Affected components: nitrogen oxide sensor (Position 2)
- 2020 GMC Sierra HD (with 6.6L L5P Duramax diesel engine)
- 2020 Chevy Silverado HD (with 6.6L L5P Duramax diesel engine)
Next steps: GM will notify owners of affected vehicles and instruct them to make an appointment with their dealership. Owners can also use the contact information below to reach out to Chevy or GMC customer service with any questions or concerns they may have. This service update will expire at the end of the GM New Vehicle Limited Warranty Period for affected vehicles, which is valid for up to three years or 36,000 miles.
- GM Customer Satisfaction Program number: N212318850
- Chevrolet Customer Service: 1-800-222-1020
- GMC Customer Service: 1-800-462-8782