P2033 indicates the powertrain control module has detected a voltage signal from the exhaust gas temperature (EGT) sensor 2 on bank 1 that exceeds the maximum expected threshold, typically signaling an open circuit or short to voltage. This sensor monitors exhaust temperature downstream of the diesel particulate filter or catalytic converter to protect aftertreatment components.
The sensor element fractures or degrades, creating infinite resistance that the PCM reads as maximum voltage.
Chafed, melted, or corroded wires and terminals in the sensor harness create high resistance or an open circuit.
A leak upstream of sensor 2 allows ambient air to cool the exhaust, causing erratic or out-of-range readings.
Soot or oil ash buildup insulates the thermistor, altering its resistance curve and producing a high-voltage signal.
Internal driver circuit failure or software calibration error misinterprets a valid sensor signal; verify all wiring and sensor integrity before considering module replacement.
The vehicle may enter reduced-power mode to protect the aftertreatment system; extended driving risks catalyst or DPF damage.
No. An EGT sensor measures temperature using a thermistor; an oxygen sensor measures exhaust oxygen content using a zirconia or wideband element.
If carbon fouling is the sole cause, careful cleaning may restore function, but a fractured element or internal open circuit requires sensor replacement.
PCM failure is extremely rare for this code. The vast majority of P2033 repairs are resolved by replacing the sensor or repairing its wiring; condemn the PCM only after exhaustive circuit and component testing.