Recall 23V024 affects 43 2019, 2021, 2022, 2023 Mack Lrbe (Electric) trucks for overheating coolant heaters. Repair is free at any franchised Mack dealer.
Mack is recalling 43 2019, 2021, 2022, 2023 Lrbe (Electric) trucks because the cabin heater relay can fail and let the coolant heater overheat. An overheated coolant heater can increase the risk of fire, and Mack dealers will complete the recall repair free of charge.
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What's wrong?
The cabin heater relay in the Mack 2019, 2021, 2022, 2023 Lrbe (Electric) is an electrical switch for the truck's heater circuit. When the key is in the ignition and the cabin heater is on, the relay opens and closes to send power only when the heater is supposed to run. That switching matters because the heater also depends on coolant flow to carry heat away.
In NHTSA campaign 23V024, the relay can fail in the closed position while the truck is energized. If that happens with no coolant flow or with a low coolant level, the coolant heater keeps heating without enough cooling around it. The heater can overheat enough to start a fire.
There is no known warning sign before failure. Mack's repair adds software that counts relay actuations, flags the truck for maintenance when the limit is reached, and disables the heater if the actuation limit is exceeded.
Who's affected?
The scope spans nonconsecutive model years for the same electric truck configuration, all tied to the same relay and wiring component.
| 2023 Mack Lrbe (Electric) | wiring |
|---|---|
| 2021 Mack Lrbe (Electric) | wiring |
| 2019 Mack Lrbe (Electric) | wiring |
| 2022 Mack Lrbe (Electric) | wiring |
| Units affected | 43 |
| Field incidents | NHTSA has logged no field incidents to date. |
A matching year and model does not guarantee inclusion. Check your VIN to confirm whether your specific truck is included.
What's the safety risk?
The coolant heater can overheat, increasing the risk of fire. There are no known warning signs before the problem occurs, so an included vehicle needs prompt dealer service instead of waiting for symptoms. Repair is free at any franchised Mack dealer.
What should I do?
- Check your VIN to confirm your 2019, 2021, 2022, 2023 Mack Lrbe (Electric) truck is included in this recall.
- Contact a franchised Mack dealer to schedule the free software update and relay replacement that fixes the cabin-heater relay overheating risk.
- Bring the recall notice if Mack mailed one. If not, reference recall number 23V024 and Mack recall SC0440 when you call.
- Call Mack customer service at 1-800-866-1177 with questions before your appointment.
- Complete the dealer repair before relying on the cabin heater in regular service.
What happens at the repair
At the dealer, a Mack technician updates the software for the Hybrid Powertrain Control Unit and instrument cluster, then installs replacement relays for the cabin heater circuit. The recall repair is free, including parts and labor. Mack's standard reimbursement plan covers documented out-of-pocket costs for qualifying related repairs paid before the recall notice. If you already paid for a related heater relay, coolant heater, or software repair, bring receipts and repair paperwork to the service desk.
| Reimbursement | Reimbursement available |
|---|
Timeline
| January 23, 2023 | NHTSA published the recall |
|---|---|
| January 27, 2023 | Dealer notification began |
| January 27, 2023 | Dealer notification ended |
| March 16, 2023 | Owner notification mailed |
| March 19, 2023 | Interim owner notification (was planned for this date) |
Frequently asked questions
What is recall 23V024?
Recall 23V024 covers 43 2019, 2021, 2022, and 2023 Mack Lrbe (Electric) trucks with a cabin heater relay that can fail and let the coolant heater overheat. Mack dealers will update the Hybrid Powertrain Control Unit and Instrument Cluster software and install replacement relays for free.
What should I do if my 2019, 2021, 2022, 2023 Mack Lrbe (Electric) is on this recall?
Check your VIN to confirm your specific truck is included in recall 23V024. If it is, contact a franchised Mack dealer to schedule the software updates and replacement relay installation. Reference Mack recall number SC0440 when you call. The repair is free.
Is the recall repair free?
Yes. Federal recall law requires manufacturers to repair safety defects at no cost, and Mack will provide the software updates and replacement relays free of charge at any franchised Mack dealer.
What is the safety risk in recall 23V024?
The safety risk is fire. In recall 23V024, the cabin heater relay can fail, causing the coolant heater to overheat. An overheated coolant heater increases the risk of fire, so confirmed vehicles need the free dealer repair.
When did Mack notify owners about this recall?
Mack mailed owner notification letters on March 16, 2023. If you bought the truck used or never received a letter, check your VIN and contact a franchised Mack dealer with recall number SC0440.
More information
| NHTSA campaign page | nhtsa.gov/vehicle-recalls/23V024000 |
|---|---|
| Mack customer service | 1-800-866-1177 |
| NHTSA recall # | 23V024 |
| NHTSA recall # (full) | 23V024000 |
Source documents
-
Download Recall Document (PDF) (PDF) - Download Quarterly Report (PDF)
- Download Recall Report (PDF)
- Download Recall Investigation Document (PDF) (PDF)
- Download Owner Notification Letter (PDF)
- Download Recall Acknowledgement (PDF)
- Download Owner Notice (PDF)
This article is generated from NHTSA's primary recall filings and reviewed against the source on May 20, 2026. RecallNotify does not paraphrase NHTSA's consequence language; that text is reproduced as written above. Editorial standards →