W163 2002 Mercedes ML 400 CDI Won't Start: P2030 and P2031 DTC Errors Explained

Hello everyone, and happy new year! I own a 2002 Mercedes-Benz ML 400 CDI (W163 platform). After two months of inactivity, my vehicle will not start. I charged the battery fully throughout the morning and attempted to restart it — it started for only 1–2 seconds before shutting off completely. On subsequent attempts, the engine cranks but does not ignite. The starter motor runs continuously until I turn the key to OFF to stop it. I've checked the ECM and found two persistent fault codes that remain after clearing: - P2030-004 - P2031-032 These DTCs are preventing the engine from starting. According to technical documentation, P2030 is typically associated with auxiliary heating systems (like Webasto), which my vehicle does not have. Given that both codes persist and the engine fails to start, I'm wondering if these faults are directly related to fuel injection or ignition system issues — especially since the vehicle starts briefly before stopping. Could P2031-032 (related to fuel injector control) be the primary cause? Any insights on how to diagnose or resolve this issue would be greatly appreciated. Best regards, Laurent