P246AExhaust Gas Temperature Sensor Circuit Intermittent/Erratic (Bank 2 Sensor 3)
- Generic OBD-II code · Powertrain
- Turns on the check-engine light
- Matters for the ITP
- How the car detects it
- P246A flags a third bank 2 exhaust temperature probe whose reading jumps from sample to sample faster than real gas temperature could, even though every single value stays inside the legal range. The bank 2 code itself is not described by any manufacturer in public material. GM's diesel tables run the equivalent quick-change test for other probes every 100 ms: the 2025 tables count a step above 100 °C between samples, fail after 12 of 25 samples and confirm the fault in a second trip (Type B). CARB expects such erratic-signal checks on emission inputs. Loose terminals, corroded pins and harness strands weakened by heat and vibration are the usual reasons, sometimes a cracked sensor element. A steady but wrong value is P2467, a permanent short or open P2468 or P2469.
- What you may notice
- MIL on after a repeated fault
- Temperature trace jumps in live data
- Fault may come and go with bumps or engine heat
- Likely causes
- LikelyLoose or corroded terminal in the probe connector
- PossibleHarness strands broken by heat and vibration
- RareCracked sensing element giving unstable contact
- 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: €0 – €350
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.