Code Definition

B1854 — Climate Control Air Temperature Internal Sensor Motor Circuit Open

System: Body  |  Type: Manufacturer-Specific  |  Make: Generic

About B1854

B1854 is a manufacturer-specific body diagnostic trouble code. It belongs to the B-prefix family of codes, which covers body, interior, airbag, or comfort-electronics faults.

When B1854 is stored, the module has detected an open (broken or disconnected) electrical path in the monitored circuit; and a sensor-related fault — the reported value from the named sensor is out of spec.

Scanning & clearing: Body (B) codes are often stored in the body control module, airbag module, or climate module. A basic OBD-II tool usually will not read body codes — an enhanced or OEM-level scan tool is typically required.

B1854 is a manufacturer-specific code. The same code string on a different make may have a different meaning. Always confirm the code's definition against the vehicle's service information for the specific make and model under test.

Code Information

The climate control module relies on an interior cabin air temperature sensor to measure actual cabin temperature for automatic blend door and fan control, and the sensor assembly contains a small aspirator motor that draws cabin air across the thermistor for accurate sampling. DTC B1854 is set when the climate control module commands the aspirator motor and detects an open circuit on the motor drive line, drawing no current at all when the motor is commanded on. The open is electrical rather than mechanical, meaning the motor winding, drive wire, or ground return has broken continuity. When t...

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