DTC B1105[16] Inside Air Temperature Sensor: Short to Ground (Auto A/C)

1. DTC B1105[16] description

The inside air temperature sensor is installed to the back side of the instrument panel (lower side). The inside air temperature sensor is a variable resistor that measures the temperature in the vehicle cabin. This sensor has a signal circuit and a low reference circuit. The auto A/C control unit supplies 5 V to the signal circuit and connects the ground to the low reference circuit. The sensor resistance increases as the temperature in the vehicle cabin decreases, and the sensor resistance decreases as the temperature in the vehicle cabin increases. The auto A/C control unit detects a high voltage when the sensor resistance is high, and a low voltage when the sensor resistance is low. If the auto A/C control unit detects that the signal voltage is excessively low, the DTC is set.

2. Condition for setting DTC B1105[16]

Condition for running the DTC

The following are met for 5 seconds or more:

  • The ignition switch is ON.
  • The ignition voltage is 10 V or more.

Condition for setting the DTC

  • The automatic A/C control unit detects that the inside air temperature sensor signal voltage is excessively low for 4 seconds or more.

3. Action taken when DTC B1105[16] sets

  • The auto A/C control unit sets the inside air temperature to the default value (25°C {77°F}).
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