Code Definition

P0079 — Exhaust Valve Control Solenoid Circuit Low (Bank 1)

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

About P0079

P0079 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 P0079 is stored, the module has detected a signal or supply voltage lower than the expected operating range; and a bank-specific fault, meaning it applies only to one cylinder bank of a multi-bank engine.

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 P0079 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 P0079 code indicates a low voltage condition in the control circuit of the exhaust valve control solenoid for Bank 1. This solenoid is an integral part of the engine's variable valve timing (VVT) system, playing a crucial role in regulating the timing and operation of the exhaust valves. The Engine Control Module (ECM) sets this code when it detects that the voltage in the solenoid circuit is lower than expected, which can have an adverse impact on the engine's exhaust valve functionality, affecting performance, emissions, and fuel efficiency.

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