U0691Lost Communication With Exhaust Pressure Sensor A
- Generic OBD-II code · Network
- Turns on the check-engine light
- Matters for the ITP
- Can trigger limp mode
- How the car detects it
- On Ford's 6.7 L and 3.0 L diesels of 2023, exhaust pressure sensor A measures pressure ahead of the turbine and is a SENT device. Ford's diesel OBD summary sets U0691 when the low-level SENT driver sees a communication error or no data within the expected window, when the line is held at one voltage level, or when the sensor reports an internal fault; the check runs continuously and needs 5 s. P0470 is kept for a SENT status error or a raw value above a limit. The same sensor has two plausibility tests: with the engine off it may differ from barometric pressure by no more than 15 kPa (P0471), and while driving it is compared against a model (P0474). Without this pressure, turbo and EGR control lose an input. U0692 covers sensor B.
- What you may notice
- Check engine light
- Reduced boost or power on some engines
- EGR and turbo running on substitute values
- Likely causes
- LikelySENT line shorted to ground or supply, or open, near the hot turbo
- PossibleSensor reports an internal error or stops sending
- PossibleConnector heat-damaged or corroded
- RareSensor damaged by soot or condensate in the pressure line
- 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.