P20E3 code meaning
Exhaust Gas Temperature Sensor 1/3 Correlation (Bank 1)
Powertrain system Generic code P20xx codes Check engine light
What P20E3 means
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.
P20E3 at a glance
- Check engine lightYes, usually on
- Emissions testCan fail
- Limp modeNot expected
- Repair difficultyMedium, DIY possible
- Typical labor0.5 to 2.5 hours
- Clears after repairAfter a drive cycle
Symptoms of P20E3
- Malfunction indicator lamp on
- Particulate filter regeneration postponed
- Temperature values of sensors 1 and 3 differ noticeably on a cold engine
Common causes of P20E3
- Most likelySensor 1 or sensor 3 reading offset or responding sluggishly
- PossibleWater or corrosion in the connector of the rear sensor
- Less likelyExhaust leak near one sensor letting outside air cool its tip
Check the most likely causes first. Replacing parts by guesswork is the most expensive way to clear a code.
Parts involved
Exhaust gas temperature sensorWiring harness
What each part of P20E3 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. |
| E3 | The exact fault in that area. |
What to do next
- Note P20E3 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 P20E3
What does P20E3 mean?
P20E3 means "Exhaust Gas Temperature Sensor 1/3 Correlation (Bank 1)". P20E3 reports that exhaust temperature sensors 1 and 3 on bank 1 do not agree. It is a generic code, so it means the same on every make.
Is it safe to drive with P20E3?
Usually yes, for a short time, if the check engine light is steady and the car drives normally. If the light flashes or the car runs badly, stop and have it checked.
Will P20E3 fail an emissions test?
Yes, it can. P20E3 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 P20E3 to fix?
Difficulty: medium. A typical repair takes 0.5 to 2.5 hours of work. A careful DIY repair is possible with basic tools and a scanner.
Will P20E3 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.