P20E3Exhaust Gas Temperature Sensor 1/3 Correlation (Bank 1)
- Generic OBD-II code · Powertrain
- Turns on the check-engine light
- Matters for the ITP
- Needs a drive cycle to confirm a fix
- How the car detects it
- P20E3 reports that exhaust temperature sensors 1 and 3 on bank 1 do not agree. In the usual diesel order, sensor 1 measures before the oxidation catalyst and sensor 3 after the particulate filter, so this pair brackets the whole aftertreatment line. No manufacturer documents this exact code publicly. Navistar's patent US7533519 explains the principle with sensors at the catalyst inlet, filter inlet and filter outlet: after a long stop all three must have cooled to almost the same value, and every pairwise difference is checked to expose a sensor stuck inside its range. Ford's 2023 diesels perform a comparable cold check (50 °C limit after 6 h off) but store P2080, P2084, P242B or P24C2 instead. CARB demands such plausibility checks for temperature sensors used by emission strategies. Expect the MIL; filter regeneration may be held back.
- What you may notice
- Malfunction indicator lamp on
- Particulate filter regeneration postponed
- Temperature values of sensors 1 and 3 differ noticeably on a cold engine
- Likely causes
- LikelySensor 1 or sensor 3 reading offset or responding sluggishly
- PossibleWater or corrosion in the connector of the rear sensor
- RareExhaust leak near one sensor letting outside air cool its tip
- 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 – €400
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.