P2085 – Exhaust Gas Temperature Sensor Circuit Intermittent Bank 1 Sensor 2 (OBD2)
P2085 means "Exhaust Gas Temperature Sensor Circuit Intermittent Bank 1 Sensor 2". The exhaust gas temperature (EGT) sensor signal briefly drops out or jumps. The fault comes and goes – often with vibration, heat or moisture – so the part may test fine in the workshop.
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P2085 quick summary
| Fault code | P2085 |
|---|---|
| Meaning | Exhaust Gas Temperature Sensor Circuit Intermittent Bank 1 Sensor 2 |
| System | Powertrain (Engine & Transmission) |
| Vehicles | Generic OBD2 |
| Severity | Medium |
| Can I drive? | Yes, gently. On diesels DPF regeneration may stop, so have it fixed before the filter clogs. |
| Repair cost | €40 – €300 |
How exhaust gas temperature sensors work
Exhaust gas temperature sensors measure the exhaust temperature at several points to protect the turbocharger and catalytic converter and to control DPF regeneration.
EGT sensors are thermistor or thermocouple-type sensors screwed into the exhaust – typically before the turbocharger, before the oxidation catalyst and before or after the DPF on diesels. They measure temperatures from below zero up to around 900–1,000 °C.
The control unit uses the readings to protect components from overheating (it reduces power when temperatures get too high) and to control DPF regeneration, which needs exhaust temperatures around 600 °C. Codes P0544–P0549 report circuit faults for sensor 1 of bank 1 and bank 2.
Sensors fail from heat cycling, their cables are damaged by heat and vibration, and connectors corrode. A faulty EGT sensor on a diesel often stops DPF regeneration, which can lead to DPF blockage codes.
Bank 1 is the side of the engine that contains cylinder 1. In-line engines (three, four, five or six cylinders in a row) have only bank 1.
Symptoms of P2085
- Check Engine light on
- DPF regeneration not completing, DPF warning
- Reduced power or limp mode
- Implausible temperature readings in live data
- Often no driving symptoms
Most common causes of P2085 (most likely first)
Mechanic's Pro Tip
EGT sensors are often seized in the exhaust. Apply penetrating oil and loosen them with the exhaust warm (not hot) – a snapped sensor thread turns a cheap job into an expensive one.
1.Loose or corroded connector pin
Most likelyPins that have spread lose contact as the engine vibrates.
2.Chafed wire that shorts only now and then
Often where the harness moves with the engine.
3.Internal intermittent fault in the exhaust gas temperature (EGT) sensor
4.Failed EGT sensor
Heat cycling breaks the sensing element.
5.Damaged sensor cable
Melted or broken near hot exhaust parts.
6.Wiring fault to the control unit
7.Exhaust leak near the sensor
Step-by-step diagnostic guide
- 1
Read codes and compare temperatures
Read all codes. On a cold engine all EGT sensors should show roughly the outside temperature.
- 2
Do a wiggle test
With the engine running and the exhaust gas temperature (EGT) sensor value in live data, gently move the harness and connector. If the value jumps or the code returns, the fault is in that section. Also check pin tension with a matching terminal.
- 3
Check the cable and connector
Inspect the sensor cable along its length for heat damage and the connector for corrosion.
- 4
Measure the sensor
Measure the resistance and compare with the specification.
Multimeter: Many PTC/NTC EGT sensors read roughly 200–250 Ω at room temperature (PT200 type); check the type for your sensor.
- 5
Check wiring
Check the wiring to the control unit for opens and shorts.
- 6
Replace and verify
Replace the sensor using anti-seize on the thread, clear codes and check that DPF regeneration completes.
Frequently asked questions
Can I keep driving with P2085?
Yes, gently. On diesels DPF regeneration may stop, so have it fixed before the filter clogs.
How much does it cost to fix P2085?
Typical repair costs are 40 € – 300 €, depending on the cause and the vehicle. The most common fixes are: loose or corroded connector pin; chafed wire that shorts only now and then; internal intermittent fault in the exhaust gas temperature (EGT) sensor. Always confirm the cause with the tests above before buying parts.
Can a bad EGT sensor block the DPF?
Indirectly yes. Without a reliable temperature signal the control unit may not start or finish regenerations, so soot builds up.
How many EGT sensors does a car have?
Petrol engines may have one or none; modern diesels often have two to four.
What is the difference between P2085 and similar codes?
P2085 belongs to a group of codes for the same component that differ in the type or location of the fault: P2036 – Exhaust Gas Temperature Sensor Circuit High Bank 2 Sensor 2; P2080 – Exhaust Gas Temperature Sensor Range/Performance Bank 1 Sensor 1; P2081 – Exhaust Gas Temperature Sensor Circuit Intermittent Bank 1 Sensor 1; P2082 – Exhaust Gas Temperature Sensor Range/Performance Bank 2 Sensor 1; P2083 – Exhaust Gas Temperature Sensor Circuit Intermittent Bank 2 Sensor 1; P2084 – Exhaust Gas Temperature Sensor Range/Performance Bank 1 Sensor 2. The tests on this page apply to the whole group; the type of fault tells you where to start.
Related fault codes
- P2084Exhaust Gas Temperature Sensor Range/Performance Bank 1 Sensor 2
- P2083Exhaust Gas Temperature Sensor Circuit Intermittent Bank 2 Sensor 1
- P2082Exhaust Gas Temperature Sensor Range/Performance Bank 2 Sensor 1
- P2081Exhaust Gas Temperature Sensor Circuit Intermittent Bank 1 Sensor 1
- P2080Exhaust Gas Temperature Sensor Range/Performance Bank 1 Sensor 1
- P2036Exhaust Gas Temperature Sensor Circuit High Bank 2 Sensor 2
- P2035Exhaust Gas Temperature Sensor Circuit Low Bank 2 Sensor 2
- P2034Exhaust Gas Temperature Sensor Circuit Bank 2 Sensor 2
This guide is for information only. Working on vehicles can be dangerous — if you are unsure, have the car checked by a qualified mechanic. Values can differ between model years; always check the manufacturer's repair information.