In this article I’ll show you how I replaced my ignition coil harness sockets. The clips were broken off and melted, and the sockets themselves were so brittle from heat that they just snapped apart during coil/spark plug maintenance. This can cause P0351, P0352, P0353, P0354 CEL codes.
Melted or broken tabs
Over time, the OEM harness clips have melted or snapped. At the time of replacement, I had over 240k original miles on these sockets. It was at the point that whenever I would touch the harness to check a coil or spark plug, they would be so brittle they would crack or disintegrate, potentially causing a bad connection.
Replacing the sockets
The new harnesses included wires, but I opted to just replace the socket (black housing and white inserts).
1. Remove the white insert.
2. Remove each wire by pushing the small black tab and pull off the wire from the back.
3. Repeat the process on the car ONE WIRE AT A TIME so that you dont goof up the order.
4. Repeat for all 4 coil harnesses
Use a pick tool to extract the white clip
depinning the 1st gen scion tc ignition coil pack harness depin
IMPORTANT: Reinstall the wires one at a time
Final Product
