Powertrain, generic (extended)

P2085 Exhaust Gas Temperature Sensor Circuit Intermittent (Bank 1 Sensor 2)

Check engine lightOn
EmissionsRelevant
Drive cycleNot required
Limp modePossible

P2085 marks the signal of exhaust temperature sensor 2 on bank 1 as erratic. GM monitors it with the same logic as sensor 1 but on separate counters. In the diesel table 18OBDG04 a step of more than 10 ohms between two 100 ms samples counts as a failure, and 20 failures within 40 samples set the code; on the 3.0 L LZO (25OBDG04B) a raw jump above 100 °C in 12 of 25 samples is enough. Both carry Type B, so the lamp needs a second faulty trip. Ford's 2014 petrol list shows P2085 without the lamp marker. Because sensor 2 often sits under the vehicle, splashed water and road salt in the connector are frequent triggers. Implausible but stable readings set P2084.

Likely causes

Water or road salt in the underbody sensor connector
Lead rubbing on the exhaust or a bracket, intermittent break
Internal fault in the sensor causing unstable resistance

Symptoms

  • Engine warning lamp on after repeated occurrence
  • Erratic sensor 2 value in live data
  • Regeneration interrupted

Repair estimate

DifficultyMediumDIY possible
Parts and labour€0–350
Time0.3–1.5 h

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

Parts involved

exhaust gas temperature sensoregt harness

Related codes

P2081P2084P2087P2031P2032P2033

References: gsi.ext.gm.com, gsi.ext.gm.com, performanceparts.ford.com.