AI Damage2021 MCI J4500: common problems
The maker issued 18 service bulletins for this year. Details by component below, with sources.
Key figures
- Technical service bulletins (TSB)
- 18
Components owners complain about
| Component | Owner complaints | involving a crash | Technical service bulletins (TSB) |
|---|---|---|---|
| Electrical system | 0 | 0 | 7 |
| Engine | 0 | 0 | 3 |
| Engine and cooling | 0 | 0 | 3 |
| Equipment | 0 | 0 | 3 |
| Fuel/propulsion system | 0 | 0 | 2 |
| Structure | 0 | 0 | 2 |
| Fuel system | 0 | 0 | 1 |
| Seats | 0 | 0 | 1 |
| Service brakes | 0 | 0 | 1 |
| Steering | 0 | 0 | 1 |
| Suspension | 0 | 0 | 1 |
| Other | 0 | 0 | 1 |
Comparison
What to check before buying
- Electrical system. Scan all modules, test the battery and alternator, inspect connectors near the impact zone.
- Engine. Cold start, unusual noises, oil leaks and engine codes.
- Engine and cooling. Radiator and fan after a frontal hit, coolant level and condition, overheating.
- Fuel/propulsion system. Fuel smell, leaks, rough running, fuel-system codes.
Manufacturer service bulletins
Bulletin titles as filed with NHTSA.
- ITS to replace the neck fill assembly with a new design which resolves a possible splashback issue at…
ITS to replace the neck fill assembly with a new design which resolves a possible splashback issue at higher fuel flow rates, without the need for fuel tank removal.
- This bulletin is to provide instructions for clearing DTC 1067 FMI 7 (Pressure Sensor Not Calibrated) and…
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…
- This bulletin introduces an optional product improvement to the A/C compressor drive system for coaches…
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…
- 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.
- Instructions to remove DEF sensor bypass calibration from engine ECM and new sensor installation AR -…
- This TSIB is to inform customers the recommended steering axle cleaning/greasing instructions to prevent…
This TSIB is to inform customers the recommended steering axle cleaning/greasing instructions to prevent damage on axle components due to displacement of grease from the bearings, lubrication reduction and accelerate…
- Instructions to download BCC program (T35-1581) V4.06
This program will allow the Eco-Temp system to properly log A17 code for low suction pressure.
- The mini fuses in the battery compartment for the condenser may not be enough for certain load conditions
- Information to owners showing the proper procedure for checking the oil level in a BITZER HVAC compressor
- Instructions to improve sealing in the front junction box
- MCI has released Technical Service Information Bulletin (TSIB) 22-12 to address concerns with water…
MCI has released Technical Service Information Bulletin (TSIB) 22-12 to address concerns with water ingress in remote switch box. The TSIB provides guidance on how to rework the box to inhibit water intrusion and…
- Technical Service Information Bulletin describing the retrofit for the front junction box cover on…
Technical Service Information Bulletin describing the retrofit for the front junction box cover on specifically equipped buses.
NHTSA lists 18 bulletins for this year; the 12 newest are shown here.
Other years of this model
Questions and answers
What are the most common problems with the 2021 MCI J4500?
There are no owner complaints in the NHTSA data for this year; the data comes from 18 manufacturer service bulletins.
How many service bulletins (TSB) were issued for the 2021 MCI J4500?
NHTSA lists 18 manufacturer service bulletins for this year. A bulletin tells dealers how to diagnose or fix a known issue; it is not a recall.
Should I buy a 2021 MCI J4500 from a US auction?
Owner complaints describe defects, not crash damage. Before bidding, check the components listed above and review the lot photos: VinWind builds a report of visible and hidden damage by VIN.
Other 2021 models
Read also
Sources: public NHTSA data (USA): service bulletins and owner complaints; YouTube: links to videos credited to their authors. Complaints are owner statements not verified by NHTSA, and describe defects rather than crash damage. Data updated 2026-11-04.