Air Temperature Sensor ( Ambient / Intake ): Testing and Inspection

Open/Shorted Intake Air Temperature Sensor Circuit:

Intake Air Temperature Sensor Circuit:

Failure Modes
DTC 24 will set if either of the following conditions are met for at least 0.50 seconds:

(1) Voltage input at the ECM indicates a very low air temperature.

(2) Voltage input at the ECM indicates a very high air temperature.

Test Description:
Numbers below refer to circled numbers on the diagnostic chart.

1. This checks for an open or short to ground in the YEL/BLK wire between the ECM and IAT sensor and for a faulty ECM.

2. This checks for an open in the BRN wire between the ECM and the IAT sensor and for a faulty ECM.

3. This determines if the problem is a faulty IAT sensor or ECM.

Diagnostic Aids:
A "shifted" (mis-scaled) sensor could result in poor driveability complaints. Measure the resistance of the IAT sensor according to the diagnostic aids chart on the diagnostic chart. If DTCs 22, 31 and 41 are also set, problem is open sensor ground circuit.

An intermittent may be caused by a poor connection, rubbed through wire insulation, or a wire broken inside the insulation. Inspect harness connectors for backed out terminals, improper mating, broken locks, improperly formed or damaged terminals and poor terminal-to-wire connections before component replacement.