2021 Mci D4000 problems, complaints & recalls
Safety recalls (1)
Fuel System, Diesel:fuel Injection System:fuel Rail 2021-12-15 · campaign 21V971000 · 1,125 vehicles
Defect: Motor Coach Industries (MCI) is recalling certain 2019-2022 D4000 ISTV, D4500, 2021 D4000, D4520, 2020-2021 D4505, D4005, 2020-2022 D45CRTLE, and 2019-2021 J4500 vehicles equipped with certain Cummins X12 diesel engines. The fuel tubes between the fuel rail and the injectors for cylinders four, five, and six may fatigue and crack, which can result in a high pressure fuel leak.
Risk: A high pressure fuel leak in the presence of an ignition source can increase the risk of a fire.
Fix: On engines with 75 miles or less, Cummins dealers will install vibration isolators to the fuel tubes. Engines with more than 75 miles will receive new fuel tubes with vibration isolators. Repairs will be performed free of charge. Owner notification letters were mailed March 11, 2022. Owners may contact MCI customer service at 1-800-241-2947. MCI's number for this recall is R21-028.
Service bulletins (8)
Technical service bulletins are repair instructions manufacturers send dealers for known issues. Unlike recalls, the fix is not automatically free — but naming the bulletin at the service desk can save diagnosis time and support goodwill repairs.
Service Brakes 2026-08-11 · TSIB 26-07 · Service Bulletin/Repair Instructions
this bulletin is to provide instructions for clearing dtc 1067 fmi 7 (pressure sensor not calibrated) and fmi 11 (primary and secondary circuit pressure sensor (ps1/ps2) plausibility error - bs pressure), when required to prevent the loss of adaptive cruise control functionality and the illuminatio
Engine 2026-06-11 · TSIB 26-05 · Service Bulletin/Repair Instructions
this bulletin introduces an optional product improvement to the a/c compressor drive system for coaches equipped with a cummins x12. the improved pulley system is available for customers who wish to reduce noise and vibration characteristics and may be installed at the customer’s discretion.
Electrical System 2026-05-06 · TSIB 26-01 · Service Bulletin/Repair Instructions
this tsib provides information to provide a software update. some coaches using mcc hvac eco-tempo ecu # 07-10-009 software t35-1581 / v1.04 may be experiencing random fault codes due to mcc software errors.
Unknown Or Other 2024-11-05 · TSIB 24-03 · Service Bulletin/Repair Instructions
information to owners showing the proper procedure for checking the oil level in a bitzer hvac compressor.
Fuel System, Diesel 2022-04-01 · TSIB 22-02 · Service Bulletin/Repair Instructions
this technical service information bulletin is a supplemental reminder to all mci owners/operators of vehicles which are affected by the cummins equipment recall 21e-099 and mci vehicle recall 21v-971.
Service Brakes, Hydraulic 2021-12-14 · TSIB 21-01 · Service Bulletin/Repair Instructions
this technical service information bulletin (tsib) describes an update from meritor for the bolt torque application requirements on hub-to-rotor bolts for the front, drive and tag axles, on specific coaches equipped with meritor ex225 disc brakes, on either conventional, preset or unitized wheel-end
Showing the 6 most recent of 8 bulletins. Search all of them free at nhtsa.gov.
What owners report
No detailed complaint narratives on file.
Excerpts of consumer complaints filed with NHTSA, lightly truncated. They are owner statements, not verified findings.