Diagnostic Aids

An intermittent may be caused by a poor connection, mis-routed harness, rubbed through wire insulation or a broken wire inside insulation. Code 48 could be caused by a vacuum leak. Check short and long term fuel trim for being in optimum range (both banks).

Fig 1: Code 48 Schematic (5.7L) Mass Airflow Sensor

Fig 2: Code 48 Diagnostic Flow Chart (5.7L)