P2471 indicates that the powertrain control module has detected a higher-than-expected voltage signal from the Bank 1 exhaust gas temperature sensor in the fourth position. This usually means the sensor circuit is reporting an out-of-range value, most often caused by a faulty sensor or an electrical fault in the wiring rather than a failed emissions component.
Internal degradation, an open sensing element, or a short inside Bank 1 Sensor 4 can cause the circuit voltage to stay high, producing an out-of-range signal to the control module.
A short-to-voltage on the signal wire, or an open or high-resistance ground circuit, can raise the circuit voltage and trigger this code, especially given the sensor's proximity to hot exhaust components.
Extreme exhaust temperatures, thermal shock, or heavy soot contamination can degrade the sensor element, housing, or seal and alter its electrical output.
Cross-threading, over-torquing, or installing a sensor with incorrect specifications can damage internal components and cause an erroneous high-voltage reading.
An internal PCM processing or analog-to-digital conversion error is a genuinely rare cause and should only be considered after the sensor and entire circuit have been thoroughly validated.
Short trips may be possible, but continued driving can interrupt DPF regeneration cycles and increase the risk of filter clogging or after-treatment system damage. Repairs should be scheduled promptly.
No. P2471 is a temperature sensor circuit fault, not a diagnosis of a failed catalyst or particulate filter. Those components generally do not need replacement solely because this code is stored.
That is usually wrong. The root cause of P2471 is almost always a defective sensor or a wiring issue. Replacing the PCM is rarely justified and should only happen after exhaustive testing proves the sensor and circuit are faultless.
Exact placement varies by vehicle, but it generally refers to the fourth exhaust gas temperature sensor in the Bank 1 exhaust stream, often located far downstream near or after the diesel particulate filter or selective catalytic reduction unit.