| 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. If ECM is replaced, ECM must be programmed with proper ignition key code for engine immobilizer system. For programming procedures, see COMPUTER RELEARN PROCEDURES article in GENERAL INFORMATION. |
Circuit Description
IAT sensor is a thermistor built into MAF sensor to monitor temperature of air flowing through MAF sensor. If DTC P0110 is set, ECM will operate in fail-safe mode. During fail-safe mode, intake air temperature parameter is fixed at 68°F (20°C). DTC P0110 is set when ECM detects an open or short in IAT sensor circuit. Possible causes are
- Open or short in IAT sensor circuit.
- Faulty IAT sensor.
- Faulty ECM.
Diagnostic Aids
After confirming DTC P0110, use scan tool to access CURRENT DATA to confirm air intake temperature. If temperature displayed on scan tool is -40°F (-40°C), IAT sensor circuit may be open. If temperature displayed on scan tool is 284°F (140°C) or more, IAT sensor circuit may be shorted. Using scan tool, read freeze frame data. Freeze frame records engine conditions when malfunction is detected.