P2084 code meaning
Exhaust Gas Temperature Sensor Circuit Range/Performance (Bank 1 Sensor 2)
Powertrain system Generic code P20xx codes Check engine light
What P2084 means
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.
P2084 at a glance
- Check engine lightYes, usually on
- Emissions testCan fail
- Limp modePossible
- Repair difficultyMedium, DIY possible
- Typical labor0.3 to 1.5 hours
- Clears after repairAfter a drive cycle
Symptoms of P2084
- Engine warning lamp on
- Particulate filter regeneration or DEF dosing restricted
- Reduced engine power on some diesels
Common causes of P2084
- Most likelySensor 2 reads low or responds slowly due to ageing or soot
- PossibleSensor connectors swapped with another exhaust temperature sensor after repair
- Less likelyOxidation catalyst not producing the expected heat, so the reading looks implausible
Check the most likely causes first. Replacing parts by guesswork is the most expensive way to clear a code.
Parts involved
Exhaust gas temperature sensor
What each part of P2084 means
| P | Powertrain system: engine, fuel system, ignition, emissions and transmission. |
| 2 | Generic code (second SAE range): it means the same on every make. |
| 0 | Area: fuel and air metering and auxiliary emission controls. |
| 84 | The exact fault in that area. |
What to do next
- Note P2084 and any other codes stored with it: several codes together often point to one cause.
- Check for loose connectors and damaged wiring around the parts the code names.
- Check open recalls for your car: some faults are fixed for free by the dealer. Enter your VIN.
- Clear the code only after the repair. If it comes back, the fault is still there.
Buying a used car? Scan it for stored codes before you pay. A recently cleared memory can hide a problem.
Questions about P2084
What does P2084 mean?
P2084 means "Exhaust Gas Temperature Sensor Circuit Range/Performance (Bank 1 Sensor 2)". 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. It is a generic code, so it means the same on every make.
Is it safe to drive with P2084?
Drive gently and only to a workshop. With P2084 the car can go into limp mode (reduced power) to protect itself.
Will P2084 fail an emissions test?
Yes, it can. P2084 is emissions-related, so most inspection programs fail a car while it is stored or while the check engine light is on.
How hard is P2084 to fix?
Difficulty: medium. A typical repair takes 0.3 to 1.5 hours of work. A careful DIY repair is possible with basic tools and a scanner.
Will P2084 clear itself after the repair?
After the repair the car has to complete a drive cycle (a mix of city and highway driving) before the test runs again. Until then the readiness monitor shows "not ready", which can fail an inspection.