P2084Exhaust Gas Temperature Sensor Circuit Range/Performance (Bank 1 Sensor 2)
- Generic OBD-II code · Powertrain
- Turns on the check-engine light
- Matters for the ITP
- Can trigger limp mode
- Needs a drive cycle to confirm a fix
- How the car detects it
- P2084 applies the plausibility check to the second exhaust temperature sensor on bank 1, on diesels usually the one behind the oxidation catalyst or ahead of the particulate filter or SCR stage. GM runs the same tests here as for sensor 1: a heat balance on the 6.6 L Duramax (15OBDG09) and a cold-soak rise check on the 3.0 L LZO (25OBDG04B), both Type B. On the Ford 6.7 L diesel, P2084 sits next to P2080 in the sensor-to-sensor check that runs after 6 h off. VW's 2014 Touareg TDI is stricter in one direction only and fails sensor 2 once it reads more than 100 K below its model. Deutz stores the plausibility fault of the sensor ahead of the SCR catalyst as P2084-62 or -64 on its EMR L1 controller. A wrong value here can upset DEF dosing and regeneration control. Unsteady readings fall under P2085.
- What you may notice
- Engine warning lamp on
- Particulate filter regeneration or DEF dosing restricted
- Reduced engine power on some diesels
- Likely causes
- LikelySensor 2 reads low or responds slowly due to ageing or soot
- PossibleSensor connectors swapped with another exhaust temperature sensor after repair
- RareOxidation catalyst not producing the expected heat, so the reading looks implausible
- Inspection (ITP)
- Matters for the ITP. While the check-engine light is on, the car fails the emissions check.
- Repair
- Medium · Often possible to do yourself.Typical cost: €60 – €350
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.