Mack LR

Published

2023-01-24

Model years

2022–2022

Issue: On a small number of LR Electric models, a relay for the coolant heater could fail. If this happens, the heater could stay energized when there is no coolant flow or a low coolant level. Safety Risk: A coolant heater that stays energized could create the risk of a fire. Corrective Actions: Mack will notify owners by mail and instruct you to take your truck to a dealership to update the hybrid powertrain control unit and instrument cluster software. The dealer will also install replacement relays.