Tiguan No-Start: Ignition Switch vs Fuel System Issues

Had the same ignition switch troubles with my 2012 Touareg TDI. The symptoms were identical, inconsistent engine start behavior when turning the key and occasional stalling. Initially thought it was just a battery issue, but the diagnostic revealed multiple problems. The main culprit was a failing ignition switch, but there was also corrosion in the car electronics wiring harness connecting to the switch. The corrosion was causing intermittent electrical connectivity issues. The repair involved replacing the complete ignition switch assembly and cleaning the surrounding electrical connections. This was definitely a serious issue that needed immediate attention, as it could have left me stranded or caused further electrical system damage. Recommend checking these specific areas: Fuse box connections for the ignition system, Wiring harness condition near the steering column, Ignition switch electrical contacts, Key tumbler mechanism The car electronics in these models are sensitive to moisture and wear. Getting it diagnosed by a certified VW specialist is important since they know the common failure points in these systems.

Thanks for sharing that experience. I had almost identical starting issues with my 2016 Tiguan, really frustrating when you never know if the car will start or not. My starter motor was fine but the ignition coil was failing intermittently. The mechanic also found some corroded wiring that needed fixing. Can you remember roughly what the total repair cost was in your case? Also wondering if you had any other electrical gremlins pop up since getting it fixed? My dash lights occasionally flicker now and I am not sure if its related.

The repair costs for my Touareg came to about 480€ total, with most of that being labor since they had to access components deep in the steering column. The defective fuse replacement was another 52€ that solved some related electrical issues. Since getting the ignition switch replaced and wiring fixed, the car starting problems have completely disappeared. The key turn is smooth now and the engine start is reliable every time. No more dashboard light issues or electrical gremlins have shown up in the past 8 months. Your flickering dash lights could indicate a separate electrical issue though. The ignition coil problems you mentioned sometimes connect to other electrical system quirks. Would suggest having the alternator output and ground connections checked, these can cause similar symptoms when they start to fail.

Thanks for the helpful advice. Finally got my Tiguan sorted out last week. Took it to a certified dealer this time, turned out you were right about the ignition coil and wiring issues. The dashboard light flickering was actually from a loose ground connection they found while doing the repair. All in it cost me 395€, which included replacing the ignition coil, fixing the corroded wiring, and sorting out the ground connection. A bit steep but worth it to have peace of mind when starting the car. The starting is perfect now, no more crossing fingers when turning the ignition key. Definitely learned my lesson about going to qualified mechanics for electrical issues. The starter motor and all other systems are working like new again.