Intake Air Temperature Sensor
| Circuit | PCM Pin | BOB Pin | Wire Color |
|---|---|---|---|
| IAT | 2J | 25 | BRN/YEL |
| SIGRTN | 2C | 46 | BLU/YEL |
1) Turn ignition off. Install BOB, leaving PCM disconnected. Measure ambient temperature at IAT, located in VAF. Measure resistance between IAT and SIGRTN test pins. Compare resistance to specifications in appropriate IAT SENSOR RESISTANCE table. If resistance is not within specification, go to next step. If resistance is within specification, IAT circuit is okay.
| Temperature °F (°C) | Ohms |
|---|---|
| -4 (-20) | 10,000-20,000 |
| 32 (0) | 4000-7000 |
| 68 (20) | 2000-3000 |
| 104 (40) | 900-1300 |
| 140 (60) | 400-700 |
2) Unplug IAT connector on VAF. Inspect IAT wire for continuity between IAT wire at connector and IAT terminal at BOB. 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 SIGRTN terminal at BOB. If resistance is less than 5 ohms, replace IAT. Repair wire as necessary.