Transmission General Information: Diagnosis
WARNING: This page is about a different car, the 2005 GMC Yukon XL, 2005 Chevrolet Suburban, and 2005 Chevrolet Avalanche. However, it is still accessible from the selected car via links, so may be relevant.
NOTE:
If you probe a wire with a sharp instrument and do not properly seal the wire afterward, the wire corrodes and an open circuit results.
Diagnostic test probes are now available that allow you to probe individual wires without leaving the wire open to the environment. These probe devices are inexpensive and easy to install, and they permanently seal the wire from corrosion.