C5 No Start
Moderator, Tech Contributor
Joined: Sep 2013
Posts: 15,424
Likes: 3,979
From: Cape Coral, Florida
You are just jumping the "load" side of the relay...you should have 12 volts through the PNP or CPP switch...you should load this circuit with a bulb...the control side is grounded through the "starter enable relay control" which comes from the BCM...if no power at the TDR yellow wire it's either the PNP/CPP, the crank fuse, ignition switch or ignition 2 fuse.
Last edited by C5 Diag; Apr 14, 2026 at 03:36 PM.
Melting Slicks
Joined: Sep 2008
Posts: 3,127
Likes: 800
From: Espanola New Mexico
Does that relay click on when you turn the key to start, by that relay I am referring to the TDR whose socket has the red and violet wires plus a smaller gauge yellow and black stripped yellow wire. If it is the TDR relay that is clicking on yet the car fails to start you should inspect the TDR socket for signs of corrosion and verify tight fitment when you plug in the relay.
