Pinpoint Test IAT - Intake Air Temperature Sensor

NOTE: Enter this test only when a Code 10 is displayed during QUICK TESTS procedure or when directed here from another PINPOINT TEST.

Fig 1: Identifying IAT Circuits

IAT CIRCUIT PIN IDENTIFICATION

Circuit	PCM Pin	BOB Pin	Wire Color
IAT	2L	27	GRN/RED
SIGRTN	2D	46	YEL/GRN

1) Turn ignition off. Install BOB, leaving PCM disconnected. Measure ambient temperature at IAT, located in air cleaner. Measure resistance between IAT and SIGRTN test pins. Compare resistance to specifications in IAT SENSOR RESISTANCE table. If resistance is not within specification, go to next step. If resistance is within specification, IAT circuit is okay.

IAT SENSOR RESISTANCE

Temperature °F (°C)	Ohms
32 (0)	72,100-79,400
55 (13)	54,300-58,600
77 (25)	29,700-36,300
110 (43)	17,900-19,300
185 (85)	3300-3700

2) Unplug IAT connector. Inspect IAT wire for continuity between IAT wire at connector and BOB test pin 27. If resistance is less than 5 ohms, go to next step. Repair wire as necessary.

3) Inspect IAT wire for shorts to ground. If resistance to ground is not less than 10,000 ohms, go to next step. Repair wire as necessary.

4) Inspect SIGRTN wire for continuity between SIGRTN wire at connector and BOB test pin 46. If resistance is less than 5 ohms, replace IAT. Repair wire as necessary.