Service bulletin 99-04-20-002N
A bulletin is a manufacturer's communication to its dealers, as NHTSA indexes it. The summary is NHTSA's. The document is the manufacturer's: read it at NHTSA. A bulletin is not a recall, and listing a model year does not mean every vehicle of it is concerned.
| Type | Service bulletin |
|---|---|
| NHTSA id | 10232275 |
| Published by NHTSA | 2023-03-03 |
| Manufacturer's number | 99-04-20-002N |
| Manufacturer's date | 2023-02-16 |
| NHTSA component | POWER TRAIN |
NHTSA's summary
This service bulletin provides information on Driveline Clunk Noise and what is acceptable and what is considered normal operation.
The document
The document is the manufacturer's. This site does not hold it. NHTSA files a document at one of these two addresses; we have not asked NHTSA which.
Components
Transmission and driveline
| BUICK CASCADA | 2016, 2017, 2018, 2019 |
|---|---|
| BUICK ENCLAVE | 2010, 2011, 2012, 2013, 2014, 2015, 2016, 2017, 2018, 2019, 2020, 2021, 2022, 2023 |
| BUICK ENCORE | 2013, 2014, 2015, 2016, 2017, 2018, 2019, 2020, 2021, 2022 |
| BUICK ENCORE | 2023 |
| BUICK ENCORE GX | 2020, 2021, 2022, 2023 |
| BUICK ENVISION | 2016, 2017, 2018, 2019, 2020, 2021, 2022, 2023 |
| BUICK LACROSSE | 2010, 2011, 2012, 2013, 2014, 2015, 2016, 2017, 2018, 2019 |
| BUICK LACROSSE | 2020 |
| BUICK LESABRE | 2013 |
| BUICK LUCERNE | 2010, 2011 |
| BUICK LUCERNE | 2012 |
| BUICK REGAL | 2010 |
| BUICK REGAL | 2011, 2012, 2013, 2014, 2015, 2016, 2017, 2018, 2019, 2020 |
| BUICK REGAL TOURX | 2018 |
| BUICK REGAL TOURX | 2020 |
| BUICK VERANO | 2012, 2013, 2014, 2015, 2016, 2017 |
| CADILLAC ATS | 2013, 2014, 2015, 2016, 2017, 2018, 2019 |
| CADILLAC ATS-V | 2015, 2016, 2017, 2018 (the catalog's model; the bulletin names a series or trim of it) |
| CADILLAC CT4 | 2020, 2021, 2022, 2023 |
| CADILLAC CT5 | 2020, 2021, 2022, 2023 |
| CADILLAC CT6 | 2013 to 2015 |
| CADILLAC CT6 | 2016, 2017, 2018, 2019, 2020 |
| CADILLAC CT6 | 2021 |
| CADILLAC CTS | 2010, 2011, 2012, 2013, 2014, 2015, 2016, 2017, 2018, 2019 |
| CADILLAC CTS-V | 2010, 2011, 2012 (the catalog's model; the bulletin names a series or trim of it) |
| CADILLAC CTS-V | 2014, 2015, 2016 (the catalog's model; the bulletin names a series or trim of it) |
| CADILLAC CTS-V | 2018 (the catalog's model; the bulletin names a series or trim of it) |
| CADILLAC DTS | 2010, 2011 |
| CADILLAC DTS | 2012 |
| CADILLAC ELR | 2014, 2015, 2016, 2017 |
| CADILLAC ESCALADE | 2010, 2011, 2012, 2013, 2014, 2015, 2016, 2017, 2018, 2019, 2020, 2021, 2022, 2023 |
| CADILLAC ESCALADE ESV | 2010, 2011, 2012, 2013, 2014, 2015, 2016 (the catalog's model; the bulletin names a series or trim of it) |
| CADILLAC ESCALADE ESV | 2017, 2018, 2019, 2020, 2021, 2022, 2023 |
| CADILLAC ESCALADE EXT | 2010, 2011, 2012, 2013, 2014 (the catalog's model; the bulletin names a series or trim of it) |
| CADILLAC ESCALADE EXT 1500 | 2010, 2011 (the catalog's model; the bulletin names a series or trim of it) |
| CADILLAC ESCALADE HYBRID | 2010, 2011, 2012, 2013, 2014 (the catalog's model; the bulletin names a series or trim of it) |
| CADILLAC ESCALADE NA | 2021 (the catalog's model; the bulletin names a series or trim of it) |
| CADILLAC LYRIQ | 2023 |
| CADILLAC SRX | 2010, 2011, 2012, 2013, 2014, 2015, 2016 |
| CADILLAC SRX | 2017 to 2019 |
| CADILLAC STS | 2010, 2011 |
| CADILLAC STS | 2012 |
| CADILLAC XT4 | 2018 |
| CADILLAC XT4 | 2019, 2020, 2021, 2022, 2023 |
| CADILLAC XT5 | 2013 to 2016 |
| CADILLAC XT5 | 2017, 2018, 2019, 2020, 2021, 2022, 2023 |
| CADILLAC XT6 | 2020, 2021, 2022, 2023 |
| CADILLAC XTS | 2013, 2014, 2015, 2016, 2017, 2018, 2019 |
| CADILLAC XTS | 2020 |
| CADILLAC redundant LYRIQ | 2023 |
| CHEVROLET 3500 | 2014 to 2015 |
| CHEVROLET 3500 | 2016 |
| CHEVROLET 3500 | 2017 to 2019 |
| CHEVROLET 3500 | 2020 |
| CHEVROLET 3500 | 2021 |
| CHEVROLET 3500 | 2022 |
| CHEVROLET 4500 | 2016 |
| CHEVROLET 4500 | 2017 to 2019 |
| CHEVROLET 4500 | 2020 |
| CHEVROLET 4500 | 2022 |
| CHEVROLET 4500HD | 2017, 2018, 2019, 2020, 2021, 2022 |
| CHEVROLET 4500XD | 2017, 2018, 2019, 2020, 2021, 2022 |
| CHEVROLET 5500HD | 2017, 2018, 2019, 2020, 2021, 2022 |
| CHEVROLET 5500XD | 2018, 2019, 2020, 2021, 2022 |
| CHEVROLET 6500 | 2019 |
| CHEVROLET 6500HD | 2022 |
| CHEVROLET AVALANCHE | 2010, 2011, 2012, 2013 |
| CHEVROLET AVALANCHE | 2014 |
| CHEVROLET AVALANCHE 1500 | 2010, 2011, 2012, 2013 (the catalog's model; the bulletin names a series or trim of it) |
| CHEVROLET AVALANCHE 2500 | 2013 (the catalog's model; the bulletin names a series or trim of it) |
| CHEVROLET AVEO | 2010, 2011, 2012, 2013, 2014, 2015, 2016, 2017, 2018 |
| CHEVROLET BLAZER | 2019, 2020, 2021, 2022, 2023 |
| CHEVROLET BOLT EUV | 2022, 2023 |
| CHEVROLET BOLT EV | 2017, 2018, 2019, 2020, 2021, 2022, 2023 |
| CHEVROLET C3500 | 2018 |
| CHEVROLET C4500 | 2010 |
| CHEVROLET CAMARO | 2010, 2011, 2012, 2013, 2014, 2015, 2016, 2017, 2018, 2019, 2020, 2021, 2022, 2023 |
| CHEVROLET CAPRICE | 2011 to 2018 |
| CHEVROLET CAPRICE POLICE PURSUIT | 2012 to 2017 |
| CHEVROLET CAPTIVA | 2010 to 2018 |
| CHEVROLET CAPTIVA SPORT | 2010, 2011, 2012 |
| CHEVROLET CHEVEROLET SS | 2014 to 2017 |
| CHEVROLET CHEYENNE | 2017 |
| CHEVROLET CITY EXPRESS | 2015, 2016 |
| CHEVROLET CITY EXPRESS | 2018 |
| CHEVROLET COBALT | 2010 |
| CHEVROLET COBALT | 2011 to 2017 |
| CHEVROLET COBALT SS | 2010 (the catalog's model; the bulletin names a series or trim of it) |
| CHEVROLET COLORADO | 2010, 2011, 2012 |
| CHEVROLET COLORADO | 2013 to 2014 |
| CHEVROLET COLORADO | 2015, 2016, 2017, 2018, 2019, 2020, 2021, 2022, 2023 |
| CHEVROLET CORVETTE | 2010, 2011, 2012, 2013, 2014, 2015, 2016, 2017, 2018, 2019, 2020, 2021, 2022, 2023 |
| CHEVROLET CRUZE | 2010, 2011, 2012, 2013, 2014, 2015, 2016, 2017, 2018, 2019 |
| CHEVROLET EQUINOX | 2010, 2011, 2012, 2013, 2014, 2015, 2016, 2017, 2018, 2019, 2020, 2021, 2022, 2023 |
| CHEVROLET EXPRESS | 2010, 2011, 2012, 2013, 2014, 2015, 2016, 2017, 2018, 2019, 2020, 2021 |
| CHEVROLET EXPRESS 1500 | 2010, 2011, 2012 (the catalog's model; the bulletin names a series or trim of it) |
| CHEVROLET EXPRESS 1500 | 2014 (the catalog's model; the bulletin names a series or trim of it) |
| CHEVROLET EXPRESS 2500 | 2010, 2011 (the catalog's model; the bulletin names a series or trim of it) |
| CHEVROLET EXPRESS 2500 | 2014 (the catalog's model; the bulletin names a series or trim of it) |
| CHEVROLET EXPRESS 2500 | 2023 (the catalog's model; the bulletin names a series or trim of it) |
| CHEVROLET EXPRESS 3500 | 2010 (the catalog's model; the bulletin names a series or trim of it) |
| CHEVROLET EXPRESS 3500 | 2012 (the catalog's model; the bulletin names a series or trim of it) |
| CHEVROLET EXPRESS 3500 | 2014 (the catalog's model; the bulletin names a series or trim of it) |
| CHEVROLET EXPRESS 3500 | 2023 (the catalog's model; the bulletin names a series or trim of it) |
| CHEVROLET EXPRESS 4500 | 2012 (the catalog's model; the bulletin names a series or trim of it) |
| CHEVROLET EXPRESS 4500 | 2014 (the catalog's model; the bulletin names a series or trim of it) |
| CHEVROLET EXPRESS 4500 | 2016 (the catalog's model; the bulletin names a series or trim of it) |
| CHEVROLET EXPRESS CUTAWAY | 2013 (the catalog's model; the bulletin names a series or trim of it) |
| CHEVROLET G VAN BUS | 2010 to 2011 |
| CHEVROLET G4500 | 2018 |
| CHEVROLET HHR | 2010, 2011 |
| CHEVROLET IMPALA | 2010, 2011, 2012, 2013, 2014, 2015, 2016, 2017, 2018, 2019, 2020 |
| CHEVROLET LOW CAB FORWARD 3500 | 2016 to 2019 |
| CHEVROLET LOW CAB FORWARD 4500 | 2016 to 2017 |
| CHEVROLET LOW CAB FORWARD 5500 | 2016 to 2017 |
| CHEVROLET LOW CAB FORWARD 6500 | 2018 |
| CHEVROLET LUMINA | 2014 |
| CHEVROLET MALIBU | 2010, 2011, 2012, 2013, 2014, 2015, 2016, 2017, 2018, 2019, 2020, 2021, 2022, 2023 |
| CHEVROLET MALIBU ECO | 2013, 2014 (the catalog's model; the bulletin names a series or trim of it) |
| CHEVROLET MALIBU HYBRID | 2010 (the catalog's model; the bulletin names a series or trim of it) |
| CHEVROLET MALIBU HYBRID | 2016, 2017, 2018, 2019 (the catalog's model; the bulletin names a series or trim of it) |
| CHEVROLET MONTE CARLO | 2010 |
| CHEVROLET N300 | 2014 to 2016 |
| CHEVROLET N300 | 2018 |
| CHEVROLET N300 MAX | 2017 |
| CHEVROLET ONIX | 2021 |
| CHEVROLET OPTRA | 2016 |
| CHEVROLET ORLANDO | 2017 |
| CHEVROLET S10 | 2016 to 2018 |
| CHEVROLET SILVERADO 1500 | 2010, 2011, 2012, 2013, 2014, 2015, 2016, 2017, 2018, 2019, 2020, 2021, 2022, 2023 (the catalog's model; the bulletin names a series or trim of it) |
| CHEVROLET SILVERADO 2500 | 2010, 2011, 2012, 2013, 2014, 2015, 2016, 2017, 2018, 2019, 2020, 2021, 2022, 2023 (the catalog's model; the bulletin names a series or trim of it) |
| CHEVROLET SILVERADO 3500 | 2010, 2011, 2012, 2013, 2014, 2015, 2016, 2017, 2018, 2019, 2020, 2021, 2022, 2023 (the catalog's model; the bulletin names a series or trim of it) |
| CHEVROLET SILVERADO 4500 | 2019, 2020, 2021, 2022, 2023 (the catalog's model; the bulletin names a series or trim of it) |
| CHEVROLET SILVERADO 5500 | 2019, 2020, 2021 (the catalog's model; the bulletin names a series or trim of it) |
| CHEVROLET SILVERADO 5500 | 2023 (the catalog's model; the bulletin names a series or trim of it) |
| CHEVROLET SILVERADO 6500 | 2019 (the catalog's model; the bulletin names a series or trim of it) |
| CHEVROLET SILVERADO 6500 | 2021, 2022, 2023 (the catalog's model; the bulletin names a series or trim of it) |
| CHEVROLET SONIC | 2011 |
| CHEVROLET SONIC | 2012, 2013, 2014, 2015, 2016, 2017, 2018, 2019, 2020 |
| CHEVROLET SPARK | 2013, 2014, 2015, 2016, 2017, 2018, 2019, 2020, 2021, 2022 |
| CHEVROLET SPARK EV | 2014, 2015, 2016, 2017 (the catalog's model; the bulletin names a series or trim of it) |
| CHEVROLET SS | 2018 |
| CHEVROLET SUBURBAN | 2010, 2011, 2012, 2013, 2014, 2015, 2016, 2017, 2018, 2019, 2020, 2021, 2022, 2023 |
| CHEVROLET SUBURBAN 1500 | 2010, 2011 (the catalog's model; the bulletin names a series or trim of it) |
| CHEVROLET SUBURBAN 1500 | 2021, 2022 (the catalog's model; the bulletin names a series or trim of it) |
| CHEVROLET SUBURBAN 2500 | 2010, 2011 (the catalog's model; the bulletin names a series or trim of it) |
| CHEVROLET T SERIES | 2010 |
| CHEVROLET TAHOE | 2010, 2011, 2012, 2013, 2014, 2015, 2016, 2017, 2018, 2019, 2020, 2021, 2022, 2023 |
| CHEVROLET TAHOE HYBRID | 2010, 2011, 2012, 2013 (the catalog's model; the bulletin names a series or trim of it) |
| CHEVROLET TAHOE POLICE PURSUIT | 2010, 2011, 2012, 2013, 2014, 2015, 2016 (the catalog's model; the bulletin names a series or trim of it) |
| CHEVROLET TRAILBLAZER | 2013 to 2014 |
| CHEVROLET TRAILBLAZER | 2017 to 2020 |
| CHEVROLET TRAILBLAZER | 2021, 2022, 2023 |
| CHEVROLET TRAVERSE | 2010, 2011, 2012, 2013, 2014, 2015, 2016, 2017, 2018, 2019, 2020, 2021, 2022, 2023 |
| CHEVROLET TRAX | 2013, 2014, 2015, 2016, 2017, 2018, 2019, 2020, 2021, 2022 |
| CHEVROLET VOLT | 2011, 2012, 2013, 2014, 2015, 2016, 2017, 2018, 2019 |
| CHEVROLET W-SERIES | 2010 to 2011 |
| CHEVROLET W3500 | 2010 |
| CHEVROLET W4500 | 2010 |
| CHEVROLET W5500 | 2010 |
| CHEVROLET duplicate SILVERADO 5500 | 2019 |
| GMC ACADIA | 2010, 2011, 2012, 2013, 2014, 2015, 2016, 2017, 2018, 2019, 2020, 2021, 2022, 2023 |
| GMC CANYON | 2010, 2011, 2012, 2013 |
| GMC CANYON | 2015, 2016, 2017, 2018, 2019, 2020, 2021, 2022, 2023 |
| GMC DENALI | 2010 to 2015 |
| GMC ENVOY | 2010 to 2013 |
| GMC G VAN BUS | 2010 to 2011 |
| GMC G3500 | 2017 to 2018 |
| GMC HUMMER EV PICKUP | 2022, 2023 |
| GMC SAVANA | 2010, 2011, 2012, 2013, 2014, 2015, 2016, 2017, 2018, 2019, 2020, 2021, 2022, 2023 |
| GMC SAVANA 1500 | 2010, 2011, 2012, 2013, 2014, 2015, 2016, 2017 (the catalog's model; the bulletin names a series or trim of it) |
| GMC SAVANA 2500 | 2010, 2011, 2012, 2013, 2014, 2015, 2016, 2017, 2018 (the catalog's model; the bulletin names a series or trim of it) |
| GMC SAVANA 3500 | 2010, 2011, 2012, 2013, 2014, 2015, 2016, 2017, 2018 (the catalog's model; the bulletin names a series or trim of it) |
| GMC SIERRA 1500 | 2010, 2011, 2012, 2013, 2014, 2015, 2016, 2017, 2018, 2019, 2020, 2021, 2022, 2023 (the catalog's model; the bulletin names a series or trim of it) |
| GMC SIERRA 2500 | 2010, 2011, 2012, 2013, 2014, 2015, 2016, 2017, 2018, 2019, 2020, 2021, 2022, 2023 (the catalog's model; the bulletin names a series or trim of it) |
| GMC SIERRA 3500 | 2010, 2011, 2012, 2013, 2014, 2015, 2016, 2017, 2018, 2019, 2020, 2021, 2022, 2023 (the catalog's model; the bulletin names a series or trim of it) |
| GMC SIERRA DENALI | 2010, 2011, 2012, 2013, 2014, 2015, 2016, 2017, 2018, 2019, 2020 (the catalog's model; the bulletin names a series or trim of it) |
| GMC T7500 | 2010 |
| GMC TERRAIN | 2010, 2011, 2012, 2013, 2014, 2015, 2016, 2017, 2018, 2019, 2020, 2021, 2022, 2023 |
| GMC TERRAIN NA | 2022 (the catalog's model; the bulletin names a series or trim of it) |
| GMC TOPKICK | 2010 to 2013 |
| GMC W-SERIES | 2010 to 2011 |
| GMC W3500 | 2010 |
| GMC W4500 | 2010 |
| GMC W5500 | 2010 |
| GMC YUKON | 2010, 2011, 2012, 2013, 2014, 2015, 2016, 2017, 2018, 2019, 2020, 2021, 2022, 2023 |
| GMC YUKON DENALI | 2010, 2011, 2012, 2013 (the catalog's model; the bulletin names a series or trim of it) |
| GMC YUKON DENALI | 2015, 2016, 2017, 2018, 2019 (the catalog's model; the bulletin names a series or trim of it) |
| GMC YUKON DENALI XL | 2010, 2011, 2012, 2013, 2014, 2015, 2016, 2017, 2018 (the catalog's model; the bulletin names a series or trim of it) |
| GMC YUKON HYBRID | 2010, 2011, 2012, 2013 (the catalog's model; the bulletin names a series or trim of it) |
| GMC YUKON XL | 2010, 2011 |
| GMC YUKON XL | 2012, 2013, 2014 (the catalog's model; the bulletin names a series or trim of it) |
| GMC YUKON XL | 2015, 2016, 2017, 2018, 2019, 2020, 2021, 2022, 2023 |
| GMC YUKON XL 1500 | 2010, 2011 (the catalog's model; the bulletin names a series or trim of it) |
| GMC YUKON XL 1500 | 2012 (the catalog's model; the bulletin names a series or trim of it) |
| GMC YUKON XL 2500 | 2010, 2011 (the catalog's model; the bulletin names a series or trim of it) |
| GMC YUKON XL 2500 | 2012, 2013 (the catalog's model; the bulletin names a series or trim of it) |
| HUMMER H2 | 2010 |
| HUMMER H3 | 2010 |
| PONTIAC G3 | 2010 |
And 12 more lines, in the JSON.
Listing a model year does not mean every vehicle of it is concerned: the document says which.
| 26V289000 | 2026-05-07. POWER TRAIN:TRANSFER CASE (4-WHEEL DRIVE) |
|---|---|
| 26V085000 | 2026-02-13. POWER TRAIN:AUTOMATIC TRANSMISSION:FLUID/LUBRICANT:VALVES/VALVE BODY; POWER TRAIN:AUTOMATIC TRANSMISSION:CONTROL MODULE:SOFTWARE |
| 2026061 | 2026-02-12. Powertrain |
| 2026060 | 2026-02-12. Powertrain |
| 26V083000 | 2026-02-12. POWER TRAIN:AUTOMATIC TRANSMISSION:CONTROL MODULE:SOFTWARE; POWER TRAIN:AUTOMATIC TRANSMISSION:FLUID/LUBRICANT:VALVES/VALVE BODY |
| 2025118 | 2025-03-06. Powertrain |
| 25V148000 | 2025-03-06. POWER TRAIN:AUTOMATIC TRANSMISSION |
| 2024679 | 2024-11-07. Powertrain |
| 24V839000 | 2024-11-07. POWER TRAIN:AUTOMATIC TRANSMISSION:CONTROL MODULE:SOFTWARE |
| 2024637 | 2024-10-24. Powertrain |
A recall listed here may apply to some of the same vehicles. Only the manufacturer can say whether it applies to one vehicle.
| 25-NA-080 | 2025-12-03. Service bulletin. This service bulletin provides a procedure to overhaul the control valve to replace a plate and worn down check ball to correct the customers concern of No Reverse, No Shift Past Third Gear - DTC P2732 Set. |
|---|---|
| 24-NA-262 | 2025-12-03. Service bulletin. This bulletin helps aid the tech in possible 10L100 transmission noise that may be normal or abnormal depending on the concern noted. |
| 25-NA-080 | 2025-10-16. Service bulletin. This service bulletin provides a procedure to overhaul the control valve to replace a plate and worn down check ball to correct the customers concern of No Reverse, No Shift Past Third Gear - DTC P2732 Set. |
| 23-NA-119 | 2025-10-16. Service bulletin. This service bulletin provides service procedure information to correct a customer concern of Shift to Park Displayed on DIC When Vehicle is in- Park, No Start - DTC B000A Set. |
| N242454441 -03 | 2025-10-09. Service campaign. Certain vehicles listed above, may have a condition where the transmission control valve has worn, resulting in a gradual loss of pressure within the valve. The effects can cause harsh shifting, setting a service engine soon message, reduced engine performance or P0747 diagnostic trouble code. Dealers are to install a new control valve body. The repairs will be made at no charge to the customer. |
| 22-NA-182 | 2025-09-27. Service bulletin. This service bulletin advises the technician to check if the transmission cooler lines are twisted to correct customer concerns of Harsh Shift, Shudder, Surge, Stall, Transmission Overheating and/or High Transmission Fluid Temperature. |
| 24-NA-078 | 2025-07-08. Service bulletin. This bulletin advises the tech to replace the starter and not the trans if grinding or growling is heard from the transmission area. |
| 21-NA-238 | 2025-07-07. Service bulletin. This technical bulletin provides a procedure to inspect the front pump of the transmission for a possible leak. |
| N252494003-01 | 2025-06-26. Service campaign. Certain vehicles listed above, may have a condition where the connecting rod and/or crankshaft engine components in these vehicles may have manufacturing defects that can lead to engine damage and engine failure. This special coverage covers if an engine failure occurs in the vehicle as a result of the condition described above for a period of 10 years or 150,000 miles (240,000 km), whichever occurs first, from the date the vehicle was originally placed in service, regardless of ownership. For vehicles covered by Vehicle Service Contracts, all eligible claims with repair orders on or after May 23, 2025, are covered by this special coverage and must be submitted using the labor operation codes provided with this bulletin. Claims with repair orders prior to May 23, 2025, must be submitted to the Service Contract provider. Vehicle owners or lessees who paid for repairs referenced in this Special Coverage (“Customers”) are eligible for reimbursement of their reasonable and customary expenses in accordance with the procedures specified below. The conditional right to reimbursement is provided by GM solely in the interest of customer satisfaction and is personal to Customers. Customers may not assign and GM does not consent to any assignment of any Customer’s right to submit reimbursement claims, or to receive reimbursement, or any other rights granted by this Special Coverage to any third party, including but not limited to service contract providers, and this Special Coverage is not intended to and does not confer any third party beneficiary, subrogation or contribution rights, or any other rights to reimbursement, against GM, whether in law, equity or otherwise, on any third parties. Dealers are to replace the engine. The repairs will be made at no charge to the customer. |
| PI0281L | 2025-06-12. Service bulletin. This preliminary informational (PI) bulletin provides information to dealership personnel that may be helpful when addressing underbody component corrosion with customers. |