VW Sharan Won't Start: ECU Issues Strike Again

Using a 2015 VW Touran TDI myself, these symptoms are familiar. When the engine fails to turn over completely, loose battery connections are often overlooked while people focus on ECU failure or engine fault codes. Last time this happened, the check engine light appeared right before the car stopped starting. The initial diagnosis pointed toward serious ECU issues, but inspection revealed heavily corroded battery terminals causing poor electrical contact. The negative terminal was particularly affected, preventing proper ground connection. The fix involved cleaning both terminals, replacing the corroded connectors, and ensuring proper terminal tightness. The engine light cleared after reconnecting everything properly. Poor battery connections can trigger various electrical issues that mimic ECU problems and cause engine stalling. For your Sharan, check these points first: Battery terminal tightness, Corrosion on connections, Cable condition near terminal ends, Ground strap integrity While this might not solve every starting issue, ruling out simple electrical problems before assuming serious engine control issues saves time and unnecessary repairs. A proper diagnosis should start with these basic checks before moving to complex electronic testing.

Thanks for sharing your experience. This is exactly what happened to my Sharan last winter. After cleaning the battery terminals the check engine light remained on, so I took it for engine diagnostics. Turned out both issues were related, corroded terminals had damaged a control module. The repair fixed all starting problems and the engine fault codes cleared up. The car runs perfectly since then. How much did the repairs end up costing in your case? Any other engine software issues since getting it fixed?

Good news, after seeing the mechanic, the engine control malfunction was completely resolved. Total cost came to 155€ for fixing the faulty battery cable connections. Much cheaper than initially feared when the check engine light first appeared. My Touran has been running smoothly since the repair with no engine surge or starting issues. The fuel injection system works perfectly now that it gets proper power. The ECU readings are all normal and no new fault codes have appeared. The key was catching those corroded connections before they could cause more extensive damage to other electrical components. When battery connections are compromised, it can trigger all sorts of misleading engine fault warnings that make diagnosis tricky. Definitely worth having a thorough electrical system check whenever starting problems occur, even if the initial symptoms point to more complex ECU failure scenarios. This preventive approach helps avoid costly repairs down the line.

Thanks for the helpful advice. Just wanted to share how it all worked out. Took the car to a mechanic who specializes in VW electrical systems after the battery check showed bigger issues. The corroded terminals had indeed caused additional problems. The engine diagnostics revealed a damaged control module that needed replacement. Total repair cost was 780€ including parts and labor. The mechanic also found and fixed some loose wiring that was causing intermittent engine stalling. Since the repair, the check engine light has stayed off and the car starts perfectly every time. Really glad I followed the advice to get a proper engine fault diagnosis instead of just cleaning the terminals and hoping for the best. Having a specialist look at it caught issues that could have led to more expensive repairs later. The whole experience taught me to take electrical problems seriously, even when they seem minor at first. Now I make sure to check the battery connections regularly as preventive maintenance.