• | Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure. |
• | Review Strategy Based Diagnosis for an overview of the diagnostic approach. |
• | Diagnostic Procedure Instructions provides an overview of each diagnostic category. |
Circuit | Short to Ground | Open/High Resistance | Short to Voltage | Signal Performance |
---|---|---|---|---|
IAT Sensor Signal | P0112 | P0113 | P0113* | P0110, P0111 |
Low Reference | -- | P0113 | P0113* | P0110, P0111 |
* Internal ECM or sensor damage may occur if the circuit is shorted to B+. |
Circuit | Short to Ground | Open | Short to Voltage |
---|---|---|---|
Operating Conditions: Engine operating in Closed Loop. Parameter Normal Range: Varies with ambient temperature. | |||
IAT Sensor Signal | 130°C (266°F), | 20°C (68°F) | 20°C (68°F)* |
Low Reference | -- | 20°C (68°F) | -- |
* Internal ECM or sensor damage may occur if the circuit is shorted to B+. |
The intake air temperature (IAT) sensor is a variable resistor that measures the temperature of the air entering the engine. The IAT sensor has a signal circuit and a low reference circuit. The engine control module (ECM) supplies 5 volts to the IAT signal circuit and a ground for the IAT low reference circuit. The ECM performs various tests to determine if the IAT is stuck in range, or out of range.
The following table illustrates the difference between temperature, resistance, and voltage:
IAT | IAT Resistance | IAT Signal Voltage |
---|---|---|
Cold | High | High |
Warm | Low | Low |
• | DTCs P0106, P0107, P0108, P0112, P0113, P0117, P0118, P0122, P0123, P0502, P0562, P0563, and P2610 are not set. |
• | The ignition is OFF for greater than 8 hours. |
• | The engine is running. |
- | The vehicle speed is less than 2 km/h (1.2 mph). |
- | The throttle position (TP) sensor is less than 2 percent. |
- | The engine is operating at idle. |
- | The above conditions are met for greater than 60 seconds. |
- | The vehicle speed is greater than 40 km/h (25 mph). |
- | The mass air flow (MAF) sensor is greater than 15 g/s. |
- | The engine is operating at a cruise. |
- | The above conditions are met for greater than 300 seconds. |
- | The calculated engine airflow is greater than 15 g/s. |
- | The vehicle speed is greater than 40 km/h (25 mph). |
- | The calculated engine airflow is greater than 15 g/s. |
- | The vehicle speed is greater than 40 km/h (25 mph). |
- | The start-up engine coolant temperature (ECT) minus the start-up intake air temperature (IAT) is greater than 20°C (36°F). |
- | The start-up ECT is greater than -20°C (-4°F). |
• | The DTCs run once an ignition cycle once the above conditions are met. |
• | Cruise Test - The ECM does not detect an intake air temperature (IAT) change of greater than 3°C (5°F). |
• | Startup Test - The ECM does not detect a difference of 3°C (5°F) between the previous ignition cycle IAT and the start-up IAT of the next ignition cycle. |
• | Skew High Test - The ECM detects a 20°C (36°F) difference between the start-up IAT and the start-up engine coolant temperature. |
• | Skew Low Test - The ECM detects a 20°C (36°F) difference between the start-up engine coolant temperature and the start-up IAT. |
DTCs P0110 and P0111 are Type B DTCs.
DTCs P0110 and P0111 are Type B DTCs.
• | If the vehicle has set overnight, the IAT sensor and the ECT sensor values should display within 3°C (5°F). |
• | The use of the engine block heater may cause DTC P0111 to set. Verify with the customer whether the block heater was in use prior to the DTC setting. |
Powertrain Diagnostic Trouble Code (DTC) Type Definitions
Control Module References for scan tool information
⇒ | If any DTCs are set, refer to Diagnostic Trouble Code (DTC) List - Vehicle. |
⇒ | If greater than the specified range, test the low reference circuit for an open/high resistance. If the circuit tests normal, replace the ECM. |
⇒ | If greater than the specified range, test the signal circuit for a short to ground. If the circuit tests normal, replace the ECM. |
⇒ | If less than the specified range, test the signal circuit for an open/high resistance. If the circuit tests normal, replace the ECM. |
Important: A thermometer can be used to test the sensor off the vehicle.
⇒ | If the resistance Vs. temperature is not within the specified range, replace the IAT sensor. |
Perform the Diagnostic Repair Verification after completing the diagnostic procedure.
• | Control Module References for engine control module replacement, setup, and programming |