What it means
Same as P245B on bank 2. EGR mixes inert exhaust into intake to lower combustion peak temperature — too little raises NOx, too much causes misfires and rough running.
At a glance
- Usually lights the check-engine light
- Affects emissions; the car can fail an emissions test
How it works
The bank 2 EGR cooler bypass controls whether exhaust gas passes through or around the cooler, while its position feedback lets the controller check that the valve follows commands. This code sets when the valve's response or feedback is outside the expected range, which can happen if the mechanism sticks, collects soot, or has a faulty actuator or sensor.
Common causes
Most likely first.
- Bypass valve sticking or binding
- Soot buildup in the bypass mechanism
- Faulty position sensor or actuator
- Damaged wiring or poor connector contact
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 commanded and reported bank 2 bypass position in live data, if available, to see how the response differs.
- Inspect the bank 2 bypass connector and harness for loose terminals, corrosion, heat damage, or wiring faults that could distort the feedback.
- With the exhaust cool, check the bypass mechanism for soot buildup or binding using the vehicle's service procedure.
- Test the bank 2 position sensor and actuator response against the manufacturer's specifications while checking that movement is not obstructed.
- If the mechanism, sensor, actuator, and wiring pass, investigate the controller's command or feedback circuit.
Common fixes
- Clean soot from the bank 2 bypass mechanism if service inspection confirms buildup.
- Repair damaged wiring or poor connector contact at the bank 2 valve.
- Free or replace a sticking bank 2 bypass valve.
- Replace the faulty bank 2 position sensor or actuator after testing identifies it.
Can I keep driving?
The fault can cause hesitation, rough running, reduced power, or knocking under load, and may increase NOx emissions. Avoid heavy loads if symptoms are present and arrange repair soon; stop if the engine runs severely or becomes unsafe to control.
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.