Diagnostic Aids

Check wiring harness routing for a potential short circuit to ground in IAT signal circuit. Scan tester displays intake air temperature in degrees centigrade. A faulty connection or an open in IAT signal circuit or sensor ground circuit will cause DTC 47 to set. Test intake air temperature sensor at various temperature levels to evaluate the possibility of a skewed (mis-scaled) sensor. See TEMPERATURE VS. RESISTANCE VALUES table. A skewed sensor could result in poor driveability complaints.

Fig 1: DTC 47 Schematic ("G" Series) IAT Sensor Circuit Low (High Temperature Indicated)

Fig 2: DTC 47 Schematic ("P" Series) IAT Sensor Circuit Low (High Temperature Indicated)

Fig 3: DTC 47 Flow Chart (All Models) IAT Sensor Circuit Low (High Temperature Indicated)