P2085 indicates an intermittent electrical fault in the exhaust gas temperature (EGT) sensor circuit for Bank 1 Sensor 2, which is typically located downstream of the catalytic converter. The signal from this sensor has become erratic or has deviated from expected values, triggering the malfunction indicator lamp (MIL).
The sensor itself has failed or is experiencing internal degradation causing intermittent readings.
Shorts, opens, or intermittent breaks in the wiring between the sensor and PCM, often from heat damage or vibration.
Poor electrical connection at the sensor connector or PCM connector due to corrosion, debris, or incomplete seating.
Exhaust leaks near the sensor location can introduce false temperature readings and affect sensor operation.
Poor or intermittent ground connection for the sensor circuit can cause erratic signal.
The powertrain control module may have an internal circuit fault, but this is rarely the cause and should be diagnosed only after all other possibilities are ruled out.
Generally yes, this is often an intermittent fault. However, if the EGT sensor is used for turbocharger protection in your vehicle, driving conditions that generate high exhaust temperatures could potentially cause engine damage if the sensor fails to alert the system.
In the majority of cases, yes. The sensor itself is the most common cause of P2085. However, it is important to first inspect the wiring and connectors, as a damaged harness will cause the new sensor to fail.
Almost never. While the PCM can fail, it is the least likely cause of P2085. A reputable technician should rule out all sensor, wiring, connector, and exhaust issues before condemning the control module. Many shops incorrectly recommend PCM replacement for this code when the actual problem is a faulty sensor or wiring issue.
Bank 1 refers to the cylinder bank containing cylinder #1 on V-engine configurations. Sensor 2 indicates the second EGT sensor in the exhaust stream, typically located downstream (after) the catalytic converter, unlike Sensor 1 which is upstream (before) the converter.