ECU Fuse Keeps Blowing after Trackday - No CEL - TT

JimmyK

Hey all, not sure if anyone cares but in case someone in the future needs to know, I did find and fix the issue.

The harness was damaged around the passenger turbo area, it didn't have the appropriate shielding upon install from the kit manufacturer (before they were outsourcing to separate shops, so no blame to them). The primary retention method was plastic zip ties which all failed due to heat exposure, and the harnessing then came in contact with exhaust-magnitude temperatures.

The harness was patched up and the shorting was most likely the crankshaft position sensor or input speed sensor. Some other small repairs were made for stripped back shielding (that wasn't shorting but was in need of repair), and the harness wrapped and staked properly, with an additional heat plate installed for both shielding and structural support.

The job required a transmission drop to physically access the damaged area, in any other location it would have been easier (except for maybe underneath the manifold), so it was just bad luck that it required a ton of effort. All the searches did support me finding the issue, so it's worth the time and effort (bull) to figure out where it is only to find out that you can't fix it. Obviously I'm salty, but it was worth it and probably lowered the repair cost quite a bit since there was minimal troubleshooting required.

Car's back to normal now, can't wait to track it again! If anyone's interested in buying a low-mile and low-track use FI TT Z, feel free to PM. It's not up on the classifieds, yet.