U068ELost Communication With EGR Temperature Sensor B
- Generic OBD-II code · Network
- Turns on the check-engine light
- Matters for the ITP
- How the car detects it
- GM documents this code in its 2025 diesel tables 25OBDG04A and 25OBDG04B, where sensor B is named EGR temperature sensor 1. Its circuit tests (P041C, P041D) are written for either a resistive probe or a digital thermocouple unit; the digital one counts as low below -72.8 °C. U068E covers the digital case: the check looks for SENT output switched off by an internal sensor fault, protocol errors or messages that are too old, and fails once 19 of 25 samples taken every 100 ms are bad while Run/Crank is active. It is Type A, so the MIL comes on in the first trip, and GM also logs a code for the input the sensor is wired to. Ford's 2023 diesels place sensor B behind the EGR cooler but read it as an analog signal. U068D, U068F and U0690 cover the other slots.
- What you may notice
- Check engine light, on GM diesels in the first trip
- Second code for the controller input stored alongside
- EGR cooler efficiency not monitored
- Likely causes
- LikelySENT signal, supply or ground wire to sensor B damaged
- PossibleInternal fault in the sensor that shuts off its output
- PossibleConnector corroded or contaminated by soot and oil
- RareFault at the controller input the sensor uses
- 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.