Diagnostic Aids
Codes 21 and 23 stored at the same time could be the result of an open Gray/Yellow wire.
Before replacing IAT sensor, refer to INTAKE AIR TEMPERATURE SENSOR RESISTANCE table. Replace IAT sensor when resistance is not as specified. A "shifted" or out of calibration IAT sensor could result in poor driveability complaints. For more IAT testing procedures, refer to I - SYS/COMP TESTS article in this section.
INTAKE AIR TEMPERATURE SENSOR RESISTANCE
| Temperature °F (°C) | Ohms |
|---|---|
| 210 (99) | 200 |
| 160 (71) | 450 |
| 100 (38) | 1300 |
| 70 (21) | 2500 |
| 40 (4) | 5200 |
| 20 (-7) | 8250 |
| 0 (-18) | 14,800 |