Intake Air Temperature Sensor: Miata
- Resistance Inspection
Disconnect Intake Air Temperature (IAT) sensor 2-pin harness connector. See Fig 1. Remove IAT sensor. Using DVOM, measure resistance between IAT sensor connector terminals "A" and "B". See IAT SENSOR RESISTANCE SPECIFICATIONS (EXCEPT MAZDA6 & MPV) table. If resistance readings are as specified, check for open or short circuit. Go to next step. If resistance readings are not as specified, replace IAT sensor. - Open Circuit Inspection
Check for continuity between following terminals:- IAT sensor harness connector terminal "B" and PCM 31-pin harness connector terminal No. 4N (Pink/Blue wire).
- IAT sensor harness connector terminal "A" and PCM 31-pin harness connector terminal No. 4O (Black/Red wire).
If continuity is present, go to next step. If continuity is not present, repair open circuit in suspect wire or replace wire harness. See appropriate WIRING DIAGRAM under ENGINE PERFORMANCE in SYSTEM WIRING DIAGRAMS.
- Short Circuit Inspection
Check for continuity to ground in Pink/Blue wire between IAT sensor harness connector terminal "B" and PCM 31-pin harness connector terminal No. 4N. If continuity is present, repair short circuit to ground in Pink/Blue wire between IAT sensor harness connector terminal "B" and PCM 31-pin harness connector terminal No. 4N.
IAT SENSOR RESISTANCE SPECIFICATIONS (EXCEPT MAZDA6 & MPV)
| Temperature - °F (°C) | Ohms | |
|---|---|---|
| Miata | ||
| 68 (20) | 2210-2690 | |
| 176 (80) | 290-354 | |
| Protege & Protege5 | ||
| 68 (20) | 2000-2900 | |
| 176 (80) | 270-370 | |