What it means
EGT sensors 1 and 3 on bank 2 disagree by more than the allowed tolerance — one is reading off, or there is a real temperature gradient that exceeds the calibrated map (e.g. from a leaking exhaust joint between the two locations).
At a glance
- Usually lights the check-engine light
- Affects emissions; the car can fail an emissions test
How it works
This code concerns the correlation between bank 2 EGT sensors 1 and 2, which measure exhaust heat at two locations for aftertreatment monitoring. It sets when their readings differ beyond the allowed range during the correlation monitor; a sensor that has drifted, a circuit fault, or an exhaust leak between the locations can cause the mismatch.
Common causes
Most likely first.
- One exhaust-gas temperature sensor has drifted or failed
- Damaged sensor wiring or connector
- Exhaust leak or unusual temperature difference between sensor locations
Symptoms
- Check-engine light on
- DPF regeneration may be affected
- Reduced engine power in some vehicles
How to diagnose it
- Use freeze-frame data and live readings to compare bank 2 EGT sensors 1 and 2 during warm-up, looking for an implausible value or a difference that grows unexpectedly.
- Inspect the connectors and heat-exposed wiring for both bank 2 sensors for chafing, melted insulation, corrosion, or loose terminals.
- Check for soot marks, loose joints, or other signs of an exhaust leak between bank 2 sensor positions 1 and 2.
- Verify both sensors are installed in the correct bank 2 locations and are seated properly.
- Test the sensors and their circuits to the manufacturer’s specification to identify a drifting sensor or wiring fault.
- If the sensor readings and circuits check out, use vehicle-specific service information to check for a control-module fault or update.
Common fixes
- Repair damaged wiring or connector terminals at bank 2 EGT sensor 1 or 2.
- Repair an exhaust leak between bank 2 sensor positions 1 and 2.
- Correct a sensor installed in the wrong location or not seated properly.
- Replace the bank 2 sensor shown by testing to be inaccurate.
- Address a confirmed control-module fault or applicable update.
Can I keep driving?
If the engine behaves normally and no aftertreatment warning indicates a restriction, a short, gentle drive to diagnosis may be possible. Avoid heavy towing or extended driving if power is reduced or regeneration warnings appear, since the module may not be able to manage exhaust temperatures reliably.
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.