FixVault

Powertrain Chart 3, Powertrain Ground Check

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

Circuit G401 is ground location for fuel pump. Circuit G104 is cooling fan and A/C compressor clutch ground. Circuit G301 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.

Fig 1: Powertrain Chart 3 Schematic (DeVille)
G94D33228Courtesy of GENERAL MOTORS CORP.
Fig 2: Powertrain Chart 3 Flow Chart (DeVille)
G94E33229Courtesy of GENERAL MOTORS CORP.