Campaign 26V-139

Engine control unit (ECU) software may allow the engine to start when the transmission is not in Neutral

Defect summary

Mack Trucks, Inc. (Mack) is recalling certain 2022-2027 TerraPro trucks. The engine control unit (ECU) software may allow the engine to start when the transmission is not in Neutral. As such, these vehicles fail to comply with the requirements of Federal Motor Vehicle Safety Standard number 102, "Transmission Shift Lever Sequence, Starter Interlock, and Transmission Braking Effect."

Consequence

Starting the vehicle while in gear may cause unexpected vehicle movement, increasing the risk of a crash or injury.

Remedy

Dealers will update the ECU software, free of charge. Owner notification letters were mailed April 14, 2026. Owners may contact Mack's customer service at 1-800-866-1177. Mack's number for this recall is SC0492. Vehicle Identification Numbers (VINs) involved in this recall became searchable on NHTSA.gov March 18, 2026.

Source: NHTSA ODI recalls file, campaign 26V139000. Text as published by NHTSA.

Vehicles covered

One product line is covered

Owner complaints filed with NHTSA about engine and cooling on these vehicles: 0, of which 0 involved a crash, fire, injury or death. Complaints are not verified by NHTSA.

Vehicles covered by campaign 26V-139
Make	Model	Model years	Complaints on this component
Mack	Terrapro (TE)	2022 to 2027	0

Source: NHTSA ODI recalls and complaints files. Equipment, tire and child-seat campaigns list products, not vehicles.

Investigation

No NHTSA investigation is linked to this recall

Most recalls are started by the manufacturer. This one lists "Manufacturer" as its origin.

Before the recall

2 service bulletins on this component came first

Distinct manufacturer communications on the same component group, make, model and model year in the 24 months before the report date.

Source: NHTSA manufacturer communications file.

Service bulletins

25V-256 Apr 17, 2025
Idler gear bracket fasteners may have been improperly tightened, allowing the idler gear to detach from the engine
23V-731 Oct 31, 2023
Rear lifting bracket that attaches to the engine cylinder head may be insufficiently secured, which can allow it to detach
22V-606 Aug 9, 2022
Engine control module (ECM) may experience an internal short-circuit, which can result in an unexpected engine shut down
15V-702 Oct 26, 2015
Affected trucks have engines with a turbocharger oil supply line that may contact or interfere with the turbocharger inlet elbow, clean air intake…
15V-275 May 11, 2015
Excessive engine crankcase pressures may cause the 90-degree elbow of the vent tube assembly to detach from the crankcase ventilation breather,…
14V-738 Nov 20, 2014
Affected vehicles contain an incorrectly wired Automatic Shut-down Protection System, which may not operate as expected