Code Definition

B2563 — Aux A/C Blower Speed 2 Circuit Failure

System: Body  |  Type: Generic (OBD-II Standard)  |  Make: Generic

About B2563

B2563 is a generic (obd-ii standard) body diagnostic trouble code. It belongs to the B-prefix family of codes, which covers body, interior, airbag, or comfort-electronics faults.

When B2563 is stored, the module has detected a signal or supply voltage lower than the expected operating range.

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.

Because B2563 is a generic OBD-II code, its base definition is shared across manufacturers. The specific diagnostic steps, reference values, and repair procedures can vary by vehicle, and the TaT Diagnostic Assistant includes verified procedures submitted by working technicians.

Code Information

The Auxiliary Climate Control Module monitors each speed output to the rear A/C blower motor to confirm correct circuit operation. DTC B2563 is set when the module detects a circuit failure on the speed 2 (typically the second lowest speed) output, indicating an open circuit, a short to ground, or a short to voltage on the speed 2 control wire between the module and the blower resistor pack. The rear blower assembly draws current through different combinations of resistor elements depending on the selected speed, and the speed 2 path uses a different resistor element than speed 1, so a failure...

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