P245B
EGR Cooler Bypass Control Circuit Range/Performance Bank 1
EGR system
Generic OBD-II
Medium
What it means
P245B sets when the EGR cooler bypass valve doesn't respond the way the ECM commands — the valve position or its feedback is out of the expected range. That valve routes exhaust either through the EGR cooler or around it, so a fault can raise emissions and, on some diesels, trigger reduced-power protection. The engine still runs.
Medium
Can I keep driving? Usually yes — the engine still runs, but expect reduced performance or higher emissions, and address it before it triggers limp mode or an emissions failure.
Common symptoms
What you'll notice
- Check-engine light on
- Reduced power or performance, especially on diesels
- Higher emissions or a failed emissions test
- Sometimes rougher running when cold
Common causes
Most likely first
- Faulty EGR cooler bypass valve or its actuatorLikely
- Valve stuck from carbon or soot buildupCommon
- Damaged wiring or connector at the bypass actuatorCommon
- Poor or corroded electrical connectionLess often
- Rarely, an ECM faultLess often
How to diagnose & fix
Work through it in order
- Read freeze-frame data and confirm the fault is present, not intermittent.
- Inspect the bypass actuator connector and wiring for damage or corrosion.
- Command the valve with a scan tool and verify it moves through its range.
- Clean carbon/soot from the valve if it is binding.
- Replace the bypass valve/actuator if it fails to track the commanded position. Clear and re-test.
FAQ
Quick answers
Is it safe to drive with P245B?+
Short-term yes — this is an emissions/EGR control fault, not a no-start. But reduced power or limp mode is possible, so get it fixed before it worsens.
Can I just clear P245B?+
It will return once the ECM re-tests the bypass valve unless the actuator, wiring, or carbon fouling is repaired.
Related codes
Often seen with P245B
Read & clear P245B yourself
Scan your car, confirm the code, and clear it once it's fixed — with OBD DashX on your phone.
✓ Verified name — SAE J2012 / ISO 15031-6Guidance reviewed by OBD DashX