Code Definition

P045C — EGR valve Circuit low Circuit B

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

About P045C

P045C is a generic (obd-ii standard) powertrain diagnostic trouble code. It belongs to the P-prefix family of codes, which covers engine, transmission, emissions, or fuel-system faults.

When P045C is stored, the module has detected a signal or supply voltage lower than the expected operating range.

Scanning & clearing: A generic OBD-II scan tool will usually read and clear powertrain (P) codes. For live data, freeze-frame capture, and bi-directional tests you may need a more capable scan tool that supports the vehicle's ECM protocol.

Because P045C 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

This fault code is set when the engine control module (ECM) detects a lower than expected voltage in the circuit of the Exhaust Gas Recirculation (EGR) valve, specifically Circuit B. A low voltage condition often points to a potential issue such as a partial short circuit, high resistance, or an electrical fault in the circuit. This can impair the EGR system's functionality, which is integral to reducing emissions by recirculating a portion of the exhaust gases back into the engine cylinders.

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