Powertrain Chart 3, Powertrain Ground Check

Circuit G401 is ground location for fuel pump. Circuit G100 is battery ground. Circuit G102 is ground for all powertrain electronics, including PCM.

Loose or poor ground connections may cause a variety of problems, including flickering telltales, PCM codes and several driveability problems. POWERTRAIN GROUND CHECK should be performed when referred to by other diagnostics or when erratic or intermittent problem is present.

These 3 vehicle grounds are essential for proper powertrain system operation. They are:

• Circuit G100, located near battery.
• Circuit G102, located on right rear corner of engine block.
• Circuit G401, located on front side of left rear seat diagonal brace.

Fig 1: Powertrain Chart 3 Schematic, Powertrain Ground Check

Courtesy of GENERAL MOTORS CORP.

Fig 2: Powertrain Chart 3 Diagnostic Flow Chart, Powertrain Ground Check

Courtesy of GENERAL MOTORS CORP.