P046DEGR Sensor A Circuit Intermittent/Erratic
- Generic OBD-II code · Powertrain
- Turns on the check-engine light
- Matters for the ITP
- Can trigger limp mode
- 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. Which part EGR sensors A and B are depends on the maker: sensor A is usually the position sensor of EGR valve A; GM's Duramax diesels of 2017/18 use sensor B for the coolant temperature sensor at the inlet of the high-pressure EGR cooler, FCA for the position sensor of the low-pressure valve. P046D means brief excursions of sensor A out of its valid range, too short for P0405/P0406. Ford petrol engines from 2020 set it when the position signal stays above 95 % or below 5 % of its range for just 0.4 s, whereas 4 s set P0405/P0406; the check runs continuously during the EGR monitor above 8.25 V and 400 rpm. EGR is then switched off.
- What you may notice
- Check engine light on, may come and go
- Usually no noticeable change
- Occasional jerking when EGR switches off
- Likely causes
- LikelyLoose contact or corrosion at the EGR valve connector
- PossibleChafed wire with brief short to ground or positive
- PossiblePosition sensor in the valve worn
- RareDisturbed 5 V reference
- Inspection (ITP)
- Matters for the ITP. While the check-engine light is on, the car fails the emissions check.
- Repair
- Easy · Often possible to do yourself.Typical cost: €30 – €600
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.