| CAUTION | If ECM replacement is instructed in following testing, always ensure ECM harness connector and ground circuit are okay. If either are suspect, repair and repeat testing to confirm ECM malfunction. |
Circuit Description
The IAT sensor is a thermistor built into the MAF sensor to monitor temperature of air flowing through MAF sensor. If DTC P0110 is set, ECM will operate in fail-safe mode (intake air temperature is fixed at 68°F (20°C)). DTC P0110 is set when ECM detects an open or short in the IAT circuit. Possible causes are
- IAT Sensor Open Or Short Circuit
- IAT Sensor
- ECM
Note. If DTCs P0110, P0115, P0120, P0450 and P1120 are output together, inspect ECM terminal E2 (ground) circuit for an open. Repair as necessary. See appropriate wiring diagram in SYSTEM WIRING DIAGRAMS article.