Circuit/System Description
WARNING: This page does not describe the selected car, but rather 6 other vehicles, including the 2018 GMC Yukon XL, 2018 GMC Yukon, 2018 Chevrolet Tahoe, 2018 Chevrolet Suburban, and 2018 Cadillac Escalade ESV. However, it is still accessible from the selected car via links, so may be relevant.
The sensors listed below are integrated within the mass air flow/multifunction intake air sensor :
- IAT sensor 1
- IAT sensor 2
- Humidity sensor
- MAF sensor
- BARO pressure sensor
The IAT sensor 2 and the humidity sensor share the same circuit. The IAT sensor 2 signal is displayed by the scan tool as Hertz (Hz) and °C (°F).
The sensors listed below share an ECM supplied 5 V reference circuit :
- IAT sensor 2
- Humidity sensor
- Barometric pressure (BARO) sensor
The sensors listed below share an ECM supplied low reference circuit :
- IAT sensor 1
- IAT sensor 2
- Humidity sensor
- Barometric pressure (BARO) sensor
IAT Sensor 1 - Temperature, Resistance, Voltage Table
| IAT Sensor 1 | IAT Sensor 1 Resistance | IAT Sensor 1 Signal Voltage |
|---|---|---|
| Cold | High | High |
| Warm | Low | Low |
IAT Sensor 2 - Temperature, Frequency Table
| IAT Sensor 2 | IAT Sensor 2 Frequency | IAT Sensor 2 Temperature |
|---|---|---|
| Cold | 45 Hz | -40°C (-40°F) |
| Warm | 302 Hz | 104°C (219°F) |