This code indicates that the engine control module has detected an intermittent signal from the exhaust gas temperature sensor located on bank 2, sensor 2 (downstream of the catalyst on the side of the engine opposite bank 1). The PCM expects a stable, predictable voltage from this sensor and is seeing readings that drop out, spike, or fluctuate outside expected parameters intermittently.
The sensor itself is the most common failure point. Internal degradation or contamination causes intermittent signal dropout, especially as the sensor heats and cools through normal exhaust cycles.
Exhaust-side wiring is exposed to high heat and vibration. Insulation can melt or chafe against chassis or exhaust components, causing intermittent shorts or open circuits.
The sensor connector can accumulate corrosion, moisture intrusion, or terminal spread, leading to intermittent contact that triggers the code.
An exhaust leak upstream of or near the sensor can cause erratic temperature readings that the PCM interprets as an intermittent electrical fault.
A failed input circuit inside the control module is rare. It should only be considered after all wiring, connectors, and the sensor have been verified good.
In most cases the vehicle will drive normally because this sensor primarily monitors exhaust conditions rather than controlling core engine operation. However, on diesel vehicles it may affect regeneration cycles, so prolonged driving without diagnosis is not recommended.
No, replacing the PCM is almost never the correct fix for this code. The exhaust gas temperature sensor, its wiring, or its connector are the actual culprits in the vast majority of cases. A PCM should only be replaced after thorough testing confirms every external component is functioning properly.
Not necessarily. While some vehicles use oxygen sensors in similar locations, this code specifically refers to an exhaust gas temperature sensor. They are different components with different functions, though they may be located in similar areas of the exhaust system.
It is generally not a drivability emergency, but it should be diagnosed within a reasonable timeframe. On diesel vehicles, an intermittent EGT sensor can prevent proper DPF regeneration, which can lead to more serious exhaust system problems if left unresolved.