Code Definition

B2545 — System Power Relay Circuit Short to Battery

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

About B2545

B2545 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 B2545 is stored, the module has detected a short-circuit (voltage pulled to ground or to supply) in the monitored circuit.

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 B2545 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 system power relay is a control module commanded relay that supplies switched battery voltage to a subsystem (commonly the climate control system, auxiliary HVAC, or another body controlled accessory load) when the relevant module energises the coil. The controlling module commands the relay coil through a low side driver and monitors the coil control circuit to confirm the relay responds correctly. DTC B2545 is set when the controlling module detects unexpected battery voltage on the relay coil control circuit at a time when the driver should have the circuit at battery voltage release (g...

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