Code Definition

P2179 — System Too Lean Off Idle (Bank 2)

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

About P2179

P2179 is a generic (obd-ii standard) powertrain diagnostic trouble code recorded for Holden vehicles. It belongs to the P-prefix family of codes, which covers engine, transmission, emissions, or fuel-system faults.

When P2179 is stored, the module has detected 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 P2179 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 Engine Control Module (ECM) monitors oxygen sensor feedback and fuel trim for bank 2 during the transition from idle to light throttle. DTC P2179 is set when, off idle on bank 2, the ECM detects a lean condition that requires excessive positive fuel trim beyond the calibrated limit to hold the commanded mixture, meaning it is adding fuel to compensate. This usually indicates insufficient fuel delivery or unmetered air affecting bank 2 during off idle operation. A lean condition can cause hesitation, surging, a lean misfire, and elevated emissions, and if severe it raises combustion tempera...

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