P2031: Exhaust Gas Temperature Sensor Circuit (Bank 1 Sensor 2)

What does P2031 mean?

Exhaust gas temperature sensor 2 on bank 1 usually sits between the oxidation catalyst and the particulate filter, where the ECM uses it to control regeneration temperature. Under the generic circuit title, manufacturers set P2031 for different faults. On Ford's 2023 diesels it is a plausibility test: after at least 6 hours off, all sensors must agree within 50 °C at key-on, and while driving each must stay within ±80 °C of the modelled temperature for 200 to 400 s, with the fault confirmed after 20 s. Mack and Volvo trucks use P2031 with a failure mode identifier for open or shorted wiring, connector faults and failed sensors, and note that regeneration is then not possible. Stellantis found water and corrosion in the sensor and harness connectors and replaces both. P2032 and P2033 are the dedicated low and high signal codes.

The code tells you which monitor failed, not which part is broken. Test before replacing parts.

Symptoms

• Malfunction indicator lamp on
• DPF regeneration inhibited

Common causes

• High Sensor failed or reading off from the model
• Medium Water or corrosion in the sensor or harness connector
• Medium Wiring open or shorted near the hot exhaust

Likelihood is a general estimate across vehicles; your make and model may differ.