Powertrain, generic (extended)

P2084 Exhaust Gas Temperature Sensor Circuit Range/Performance (Bank 1 Sensor 2)

Check engine lightOn
EmissionsRelevant
Drive cycleRequired
Limp modePossible

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.

Likely causes

Sensor 2 reads low or responds slowly due to ageing or soot
Sensor connectors swapped with another exhaust temperature sensor after repair
Oxidation catalyst not producing the expected heat, so the reading looks implausible

Symptoms

  • Engine warning lamp on
  • Particulate filter regeneration or DEF dosing restricted
  • Reduced engine power on some diesels

Repair estimate

DifficultyMediumDIY possible
Parts and labour€60–350
Time0.3–1.5 h

Typical range across vehicles; the real cost depends on what the testing finds.

Parts involved

exhaust gas temperature sensor

Related codes

P2080P2085P2086P2031P2032P2033

References: gsi.ext.gm.com, gsi.ext.gm.com, static.nhtsa.gov, serdia.deutz.com.