Excessive Time To Enter Closed Loop EGR Control
After cold start the ECU operates EGR open-loop until preconditions (cooler temperature, sensor warm-up, engine load) are met, then transitions into closed-loop control. The transition is taking too long - typically due to a slow EGR temperature sensor, a stuck EGR valve still warming up, or a long-trip drive cycle that does not meet load conditions.
Affected components
- Egr valve a
- Egr temperature sensor a
Common causes
- High likelihood: EGR temperature sensor responds slowly
- Medium likelihood: Short-trip operation - load conditions not met
Possible symptoms
- Check engine light on
- Pinging or knocking under load
- Power loss and hesitation
- Possible rough idle
- Failed emissions inspection (NOx)
Diagnostic notes
- The malfunction indicator lamp may illuminate
- This code can affect emissions
Sources
Diagnostic information is provided for reference only. Confirm the code with a compatible scan tool and follow the vehicle manufacturer's service procedures before replacing components.