P04E8EGR Temperature Sensor D Circuit High
- 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
- Exhaust gas recirculation (EGR) routes part of the exhaust back into the intake to lower combustion temperature and NOx. Sensor D is the fourth of up to four EGR temperature sensors, conceivable on engines with high- and low-pressure EGR and a sensor before and after each cooler; it is usually an NTC whose low voltage means hot. No manufacturer document available to us uses sensor D; the description follows CARB and Ford's checks on sensor B as a comparison. P04E8 means the signal is above its upper limit – an open circuit in sensor, connector, line or ground, or a short to positive; the reading looks very cold. For sensor B Ford uses above 4.95 V. A substitute value is used.
- What you may notice
- Check engine light on
- Usually no change in driving
- EGR possibly reduced, higher NOx
- Likely causes
- LikelyConnector off or loose, or pin corroded
- PossibleSensor open internally (heat damage)
- PossibleSensor ground line open
- RareSignal line shorted to positive
- 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: €50 – €250
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.