VW Sharan Electrical Issues Point to Battery Failure

I had very similar issues with my 2014 VW Touran diesel. As someone with some experience working on VWs, I initially thought it was just a failing battery, but it turned out to be more complex. The symptoms matched exactly what youre describing, weak starts, unusual electrical system warnings, and dashboard lights acting up. After dealing with this for about two weeks, I took it to a workshop that specializes in electrical diagnostics. They found the battery sensor was defective, causing incorrect readings and making the car think the battery was fine when it wasnt. This led to improper charging and eventual battery drain. The total repair came to 315€, which included diagnostic time and replacing the sensor. The fix has been solid for over a year now with no recurring electrical system issues. The battery terminals were also cleaned and checked during the repair, which is always good preventive maintenance. Before suggesting more specific solutions, could you share: Current battery age and when it was last replaced, Whether the issues occur more after short or long trips, If youve noticed any pattern with the error messages, Whether youve had any recent electrical work done, What fault codes are stored in the system This information would help determine if youre dealing with the same root cause or possibly something different.

Thanks for the detailed response. I checked my service records, last maintenance was done at 62000km just 3 months ago. The battery is actually original from 2016, which now seems likely to be the main issue given the vehicle battery symptoms you described. The errors occur mostly after short trips around town, which matches the battery drain pattern you mentioned. No recent electrical work has been done. The fault codes mainly relate to low voltage warnings, specifically showing up in the brake system and engine management. Since posting, the electrical system warnings have become more frequent, especially during cold starts. Think I will follow your advice about getting the battery sensor checked along with a full diagnosis rather than just swapping the battery blindly.

Thanks for those details. That 2016 original battery is definitely the prime suspect, 7-8 years is well beyond typical car battery lifespan, especially with mostly short trips that prevent full charging cycles. The increasing frequency of electrical system warnings during cold starts strongly suggests a discharged battery situation. My Touran showed identical symptoms before the repair, particularly the brake system and engine management warnings triggered by voltage drops. While my case involved the battery sensor, yours points more toward straightforward battery failure. The short trip pattern is particularly telling, these brief runs dont allow the charging system to fully restore battery charge levels. A few suggestions based on my experience: Get a proper battery diagnostic test rather than just voltage readings, Have the alternator output checked while testing, Consider a higher capacity battery if short trips will remain your typical usage, Request cleaning and inspection of battery terminals during replacement The workshop should scan for stored fault codes before and after repair to ensure the issues clear up. Once my battery-related problems were properly diagnosed and fixed, all those unusual electrical gremlins disappeared completely. Given the symptoms and age of your battery, addressing this now could prevent being stranded with a completely failed battery later.

Thanks for all the suggestions. I booked the car in at a repair shop next week. Given what was shared about the battery sensor issues, I specifically asked them to include checking that along with the battery test. The service advisor mentioned they are seeing a lot of electrical problems in VWs of my age, often tied to low battery voltage from original batteries still being used. Makes sense given mine is the factory-fitted unit from 2016. Since posting, I have been doing mainly longer drives to help maintain better battery charging levels. The warning lights are still appearing but seem less frequent with the extended trips. The cold start issues continue though, which reinforces this is likely more than just normal battery drain. Will update once I get the diagnostic results, but feeling more confident now about the repair direction. At minimum, I know to get both the battery terminals and sensor checked rather than just accepting a straight battery swap. Good to hear your fix has lasted over a year without those electrical gremlins returning.