What it means
The EGR sensor D signal is within an electrical range but does not match the expected value for operating conditions.
At a glance
- Usually lights the check-engine light
- Affects emissions; the car can fail an emissions test
How it works
EGR sensor D reports a value the control module uses to assess an EGR-related condition; the sensor's exact role varies by vehicle. The module checks whether that signal matches expected behavior for current operating conditions. This code sets when the signal is electrically plausible but outside the expected range or response, which may result from sensor drift or a soot-blocked reference port.
Common causes
Most likely first.
- Sensor element drifted
- Reference port partially blocked by soot
Symptoms
- Check engine light on
- Pinging or knocking under load
- Power loss and hesitation
- Possible rough idle
- Failed emissions inspection (NOx)
How to diagnose it
- Save freeze-frame data and compare EGR sensor D live data with engine load and related EGR readings to identify when it diverges from expected behavior.
- Locate sensor D and inspect its reference port for soot or deposits that could obstruct the measured condition.
- Check the sensor connector and wiring for looseness, corrosion, or damage that could distort an otherwise plausible signal.
- Use a scan tool's supported EGR test to observe whether sensor D changes as expected when EGR operation changes.
- If the port and wiring are clear and sound, test sensor D's response against the manufacturer's specification.
Common fixes
- Clear soot or blockage from sensor D's reference port using the vehicle's service procedure.
- Repair a loose or damaged sensor D connector or wiring.
- Replace EGR sensor D if its signal has drifted or fails the specified response test.
- Address an EGR passage blockage if inspection shows it is preventing the expected sensor response.
Can I keep driving?
Limit heavy-load driving if pinging, knocking, hesitation, or power loss occurs. Arrange diagnosis soon because EGR performance and emissions may be affected.
A code shows where the control module detected a fault, not always which part failed. Check the causes in order and confirm with a test before replacing parts. Have several codes? Check them together
This is a generic code: it means the same on every make. The car’s maker may add more detail in its own service information.