VW Jetta Diesel Dead: No Crank, No Start, ECU Suspect

Had a similar situation with my VW Passat TDI from 2003. The symptoms matched exactly, no cranking, no clicking, despite a good battery. The root cause was corroded and loose battery cable connections, not an ECU issue. Even though the battery tested fine, the poor connections prevented proper current flow to the starter. The engine diagnostics showed some stored codes, but they were actually related to low voltage from the bad connections. A thorough inspection revealed green corrosion at the battery terminals and a loose ground strap. The check engine light had activated due to voltage fluctuations affecting the fuel injection system. This repair required: Cleaning both battery terminals and cable ends, Replacing one corroded battery cable, Securing the ground connection, Clearing stored fault codes, Testing the charging system Not a serious repair overall, but leaving it unfixed can cause the ECU and other electronic components to behave erratically. Would recommend getting the connections checked and cleaned before assuming ECU failure, since bad connections often mimic more severe electrical issues. The fact your engine light came on recently suggests voltage-related issues, which aligns with potential connection problems. Worth having the full electrical system tested with proper engine diagnostics equipment.

Thanks for sharing that detailed solution about the battery connections. Had exactly the same symptoms with my 2001 Jetta last winter. When my car stopped starting, I immediately feared engine software issues or ECU failure, turns out it was also just corroded battery terminals causing an engine surge. The check engine light had me worried too. Did you track how much the total repair came to? Just curious since my fix included some additional preventive work on the electrical system. Also wondering if you experienced any similar issues since getting it fixed or if it solved the problem completely?

After getting the battery connections fixed and cleaned, my Passat has run perfectly without any engine fault warnings or starting issues. The engine control malfunction cleared up right after the repair was done. Total cost was 155€ for cleaning the battery terminals, replacing corroded cables, and checking all ground connections. The mechanic did a full electrical system diagnostic which confirmed the ECU issue was just a false alarm caused by voltage fluctuations. This was much cheaper than replacing ECU components, which I initially feared might be necessary when the engine surge symptoms appeared. No new problems in over a year now, the car starts immediately every time. Just maintaining clean battery connections seems to prevent those confusing engine software errors from popping up again. Getting it checked early probably saved money in the long run by avoiding damage to other electrical components.

I went to the mechanic last week to get it all sorted. The entire repair including parts and labor came to 180€. They cleaned the connections, replaced both battery cables since they were pretty corroded, and ran a complete engine diagnostics test to make sure no other systems were affected. The mechanic showed me how the voltage drops were triggering false engine light warnings and causing the ECU to act up. Since the fix, my Jetta starts perfectly every time with no warning lights or engine surge issues. Really relieved it wasnt a major electronic failure like I first thought. Would definitely recommend anyone with similar starting problems to check their battery connections first before assuming the worst. The fuel injection and other systems can get really confused when they're not getting stable power. Mine has been running great for 3 months now without any electrical gremlins coming back.