Code P048, EGR System Fault (1 Of 2): Action

PCM turns on MIL. EGR is disabled for entire key cycle.

1. Checks EGR operation using PCM override.
2. Checks if EGR gases enter intake manifold by raising EGR valve off its seat.
3. Checks if EGR solenoid passage is clear.

Fig 1: Code P048 Schematic (DeVille)

Courtesy of GENERAL MOTORS CORP.

Fig 2: Code P048 Flow Chart (DeVille - 1 Of 2)

Courtesy of GENERAL MOTORS CORP.