03 December, 2025PACCAR MX (2004 Emissions) Fault Code: P0149 Fuel Injection Control – Malfunction Detected PACCAR MX (2004 Emissions) Fault Code: P0149 Fuel Injection Control – Malfunction Detected IMPORTANT: Do not troubleshoot this DTC. POSSIBLE CAUSES:No repairs are necessary. ADDITIONAL INFORMATION:The driver is not informed by a warning when this DTC is active. Share on Facebook Opens in a new window. Tweet on Twitter Opens in a new window. Pin on Pinterest Opens in a new window. Back to blog