OBD-II code family
Mixture Control Operating Range and Bank Faults (12 codes)
12 related fault descriptions. Use each full code and the exact vehicle service information to identify its circuit, monitored condition, and required tests.
Codes in this family
This is the complete published member list for this guide. Each code retains its own page; shared diagnostic context does not mean that every member has the same test or repair.
- P2177System Too Lean Off Idle (Bank 1)
- P2178System Too Rich Off Idle (Bank 1)
- P2179System Too Lean Off Idle (Bank 2)
- P2180System Too Rich Off Idle (Bank 2)
- P2187System Too Lean at Idle (Bank 1)
- P2188System Too Rich at Idle (Bank 1)
- P2189System Too Lean at Idle (Bank 2)
- P2190System Too Rich at Idle (Bank 2)
- P2191System Too Lean at Higher Load (Bank 1)
- P2192System Too Rich at Higher Load (Bank 1)
- P2193System Too Lean at Higher Load (Bank 2)
- P2194System Too Rich at Higher Load (Bank 2)
What these codes mean
These twelve reports preserve three details together: mixture direction, operating range and bank. P2177/P2178 are lean/rich off idle on Bank 1; P2179/P2180 preserve those directions on Bank 2. P2187/P2188 concern idle on Bank 1 and P2189/P2190 idle on Bank 2. P2191/P2192 identify lean/rich at higher load on Bank 1, with P2193/P2194 the corresponding Bank 2 reports. Keep the complete designation when selecting the diagnostic procedure.
A mixture-control result does not identify a single failed part or directly measure the output of each injector. Incorrect air, pressure or oxygen-feedback information can affect the result, as can an actual air/fuel-delivery concern. The absence of a separate sensor-circuit code does not certify measurement accuracy. These system reports are distinct from a biased oxygen-sensor signal, a post-catalyst trim report or a particular injector-circuit fault.
Idle, off idle and higher load describe monitoring ranges. They are not instructions to recreate a fault by loading the vehicle on the road. Audi’s cited 2013 CEJA 6.3L tables list separate off-idle and idle adaptation criteria. A result in one range does not establish that another range was evaluated or passed; thresholds and prerequisites belong to the engine and calibration being diagnosed.
Bank 1 and Bank 2 identify the reported monitoring groups, not a universal physical side or two independent pumps, rails and airflow meters. In the archived 2005 Cayenne S V8 P2193 procedure, the diagnostic table calls for checking both airflow sensors because cylinder filling is calculated from both signals. That bounded example shows why one bank’s code cannot rule out a shared measurement concern. It does not assign two airflow meters to every engine.
Software examples also need their exact application. Hyundai bulletin 12-FL-010 describes a P2192 update for specified 2012–2013 Accent and Veloster 1.6L GDI transmission and ECM/ROM combinations. Its software remedy and statement about that case’s running behavior do not extend to every vehicle reporting a rich higher-load result. A shop should match the vehicle, calibration and current service direction before proposing programming.
Save the complete scan, freeze frame, correction or adaptation data and actual symptoms before clearing codes. Note recent intake, exhaust, fuel or sensor work. A qualified technician should follow the matched priorities and compare compatible bank/range data, then use the prescribed air-path, exhaust, measurement, electrical or fuel-delivery checks to establish the cause. A plausible graph, one correction value or a trial part is not a complete diagnosis.
Do not spray a running intake, introduce an air leak, disconnect vapor or regulator hoses, open fuel lines or force a mixture as a generic test. Ask which finding supports the proposed repair and how it will be verified. The confirmed job determines the parts, setup and estimate. Follow actual warnings and obtain help for fuel leakage, severe rough running, stalling, flashing warnings or unsafe power response; the lean/rich label cannot guarantee a safe travel distance.
Identify the circuit on your vehicle
Match the full DTC, reporting module, and any failure-type suffix to the service information for your exact year, make, model, engine, and equipment. An identifier alone does not establish installed hardware count, location, connector pinout, or a universal measurement.
Where the manufacturer publishes its own meaning for this code, that is the one to work from — it describes the actual component on your vehicle, which the generic definition cannot. Keep the generic description for what it is good for: it tells you which subject area the standard assigned the code to, which is useful context when the two appear to disagree. If they do disagree, follow the manufacturer.