This code indicates that the engine control module has detected an open circuit in the exhaust gas temperature sensor circuit for Bank 2 Sensor 5. This sensor is typically located downstream in the exhaust system, often near or after a diesel particulate filter or selective catalytic reduction system. An open circuit means the PCM is not receiving a plausible voltage or resistance signal from that sensor.
The sensor itself has an internal open or has degraded from repeated heat cycling. This is the most common cause for this code.
Exhaust heat and vibration commonly damage sensor wiring, causing an open circuit. Look for melted, broken, or chafed conductors near the exhaust.
The sensor connector pins can corrode, spread, or lose contact due to heat cycling, resulting in an open circuit at the connection.
Less common, but corrosion, pin spread, or rodent damage at the PCM connector can create an open in the sensor return or signal path.
Rare and unlikely. The control module would only be suspected after the sensor, wiring, and connector have all been fully verified as good.
Short distance driving may be possible, but on diesel applications the vehicle may derate or fail regeneration. Extended driving risks further exhaust system issues and should be avoided until repaired.
No. Replacing the PCM is almost never the correct fix for this code. The sensor, wiring, and connector are far more likely culprits and should be fully diagnosed first.
No. An exhaust gas temperature sensor measures temperature, not oxygen content. It is a thermistor-type sensor, not a wideband or narrowband O2 sensor.
Yes. If the sensor failure prevents proper DPF or SCR operation, emissions can increase and the vehicle may fail an emissions test or be flagged as not ready.