Recall 21V233 affects 557 2018-2022 Mack Anthem, Granite, Pinnacle trucks with ESC software that can let them drift lanes. Free repair at franchised Mack dealers.
Mack is recalling 557 2018-2022 Anthem (An), Granite (Gr), Granite (Gu), and Pinnacle (Cxu) trucks equipped with camelback rear suspension and electronic stability control because they can drift out of lane at certain speeds. A lane drift increases crash risk, and Mack dealers will complete the recall repair free of charge.
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What's wrong?
The electronic stability control system in the 2018-2022 Mack Anthem (An), Granite (Gr), Granite (Gu), Pinnacle (Cxu), Pinnacle (Chu), and Pinnacle (Pi/Pn) trucks helps keep the truck under control during stability-control maneuvers. Its control module uses vehicle parameter files, which are software settings that tell the system how to respond for that truck's suspension and configuration.
On affected trucks with camelback rear suspension, those parameter files used an entry speed setting that did not pass Mack's later compliance testing. During that testing, the truck did not stay within the required test lane at certain speeds. Mack traced the issue to the software settings, not to a broken suspension part.
There is no warning sign before failure. The driver is not given a dashboard alert or a distinct handling symptom before the lane-stay problem shows up under the affected stability-control conditions.
Who's affected?
Spans 6 Mack truck lines across the 2018-2022 model years, all using software tied to the electronic stability control module.
| 2022 Mack Granite (Gr) | Software |
|---|---|
| 2022 Mack Granite (Gu) | Software |
| 2022 Mack Pinnacle (Cxu) | Software |
| 2021 Mack Pinnacle (Chu) | Software |
| 2019 Mack Pinnacle (Chu) | Software |
| 2019 Mack Granite (Gr) | Software |
| 2021 Mack Granite (Gu) | Software |
| 2020 Mack Granite (Gu) | Software |
| 2019 Mack Granite (Gu) | Software |
| 2018 Mack Granite (Gu) | Software |
| 2020 Mack Pinnacle (Chu) | Software |
| 2020 Mack Granite (Gr) | Software |
| 2018 Mack Pinnacle (Chu) | Software |
| 2020 Mack Pinnacle (Cxu) | Software |
| 2019 Mack Pinnacle (Cxu) | Software |
| 2018 Mack Granite (Gr) | Software |
| 2021 Mack Granite (Gr) | Software |
| 2021 Mack Pinnacle (Cxu) | Software |
| 2022 Mack Pinnacle (Chu) | Software |
| 2022 Mack Anthem (An) | Software |
| 2021 Mack Anthem (An) | Software |
| 2018 Mack Pinnacle (Cxu) | Software |
| 2018 Mack Pinnacle (Pi/Pn) | Software |
| 2018 Mack Anthem (An) | Software |
| 2019 Mack Anthem (An) | Software |
| 2019 Mack Pinnacle (Pi/Pn) | Software |
| 2020 Mack Anthem (An) | Software |
| 2020 Mack Pinnacle (Pi/Pn) | Software |
| 2021 Mack Pinnacle (Pi/Pn) | Software |
| 2022 Mack Pinnacle (Pi/Pn) | Software |
| Units affected | 557 |
| Field incidents | NHTSA has logged no field incidents to date. |
The year and model narrow the scope, but the VIN decides. Check your VIN to confirm whether your specific truck is included.
What's the safety risk?
A vehicle that drifts out of its lane increases the risk of a crash. If you notice unintended lane drift, keep extra space, reduce speed when safe, and schedule the recall repair soon. Repair is free at any franchised Mack dealer.
What should I do?
- Check your VIN to confirm your 2018-2022 Mack Anthem (An), Granite (Gr), Granite (Gu), Pinnacle (Chu), Pinnacle (Cxu), or Pinnacle (Pi/Pn) is included in this recall.
- Contact a franchised Mack dealer to schedule the free vehicle-control-unit software reprogramming that corrects the stability-control lane-drift problem.
- Bring the recall notice if Mack mailed one. If not, reference recall number 21V233 when you call.
- Drive cautiously until the repair is complete, especially at speeds where the truck drifts from its lane.
- Call Mack customer service at 1-800-866-1177 with questions about scheduling or dealer instructions.
What happens at the repair
At the dealer, a Mack technician reprograms the vehicle control units that manage the electronic stability control system. The recall repair is available now, and parts and labor are free. Mack has a general reimbursement plan on file for owners who paid for a related repair before the recall notice. If you already paid for this issue, contact Mack customer service or ask the service desk what documentation the reimbursement plan requires.
| Reimbursement | Reimbursement available |
|---|
Timeline
| April 1, 2021 | NHTSA published the recall |
|---|---|
| April 21, 2021 | Owner notification mailed |
| April 22, 2021 | Dealer notification began |
| April 22, 2021 | Dealer notification ended |
| May 21, 2021 | VIN-searchable in NHTSA's database — Check your VIN to see whether this recall applies to your specific vehicle. |
| May 21, 2021 | Interim owner notification (was planned for this date) |
Frequently asked questions
What is recall 21V233?
Recall 21V233 covers 557 2018-2022 Mack Anthem (An), Granite (Gr), Granite (Gu), Pinnacle (Chu), Pinnacle (Cxu), and Pinnacle (Pi/Pn) vehicles with camelback rear suspension and electronic stability control. The vehicle control software can let the vehicle drift out of its lane at certain speeds, increasing crash risk.
What should I do if my 2018-2022 Mack Anthem (An), Granite (Gr), Granite (Gu), Pinnacle (Chu), Pinnacle (Cxu), or Pinnacle (Pi/Pn) is on this recall?
Check your VIN to confirm your specific vehicle is included in recall 21V233. If it is, contact a franchised Mack dealer to schedule the vehicle control unit reprogramming. Reference recall number 21V233 or Mack recall SC0423 when you call.
Is the recall repair free?
Yes. Federal recall law requires the manufacturer to repair the defect at no cost, and Mack dealers will reprogram the vehicle control units free of charge. Parts and labor are covered for included vehicles.
What is the safety risk?
The safety risk is lane drift at certain speeds. If the vehicle does not stay in its lane, the driver has less control over where the vehicle travels, increasing the risk of a crash. The dealer repair addresses the electronic stability control software issue.
When did Mack start this recall repair?
Mack began the recall repair on April 21, 2021. Owners can contact Mack customer service at 1-800-866-1177 or call a franchised Mack dealer and reference recall SC0423 to schedule the free vehicle control unit reprogramming.
More information
| NHTSA campaign page | nhtsa.gov/vehicle-recalls/21V233000 |
|---|---|
| Mack customer service | 1-800-866-1177 |
| NHTSA recall # | 21V233 |
| NHTSA recall # (full) | 21V233000 |
Source documents
-
Download Recall Document (PDF) (PDF) - Download Quarterly Report (PDF)
- Download Recall Investigation Document (PDF) (PDF)
- Download Owner Notification Letter (PDF)
- Download Owner Notice (PDF)
- Download Recall Report (PDF)
- Download Recall Acknowledgement (PDF)
This article is generated from NHTSA's primary recall filings and reviewed against the source on May 23, 2026. RecallNotify does not paraphrase NHTSA's consequence language; that text is reproduced as written above. Editorial standards →