P02D3
Cylinder 4 Fuel Injector A Offset Learning At Max Limit
Fuel injection
Generic OBD-II
High
What it means
P02D3 means the ECM's learned fueling offset for the cylinder 4 injector has reached its maximum limit — the computer can no longer compensate for how that injector is behaving. It usually points to a worn or faulty injector, or a wiring/control-module fault, causing rough running until the injector or circuit is repaired.
High
Can I keep driving? Usually driveable, but the injector fueling on cylinder 4 is off; expect rough running and fix it before it worsens or fouls the cylinder.
Common symptoms
What you'll notice
- Check-engine light on
- Rough idle or uneven running
- Hesitation or reduced power
- Possible knock or a slight misfire on cylinder 4
Common causes
Most likely first
- Worn or faulty cylinder 4 fuel injector (out of its learnable range)Likely
- Damaged wiring or a corroded connector at the injectorCommon
- Poor connection or fault in the injector control module (FICM) supply/groundCommon
- Fuel-pressure or fuel-quality issue affecting injector characterizationLess often
How to diagnose & fix
Work through it in order
- Read freeze-frame data and inspect the cylinder 4 injector wiring and connector.
- Check the injector control module's supply voltage and ground circuits.
- Test the injector against spec and compare to the other cylinders.
- Replace the worn injector and, where required, re-code/re-learn injector offsets. Clear and re-test.
FAQ
Quick answers
Is it safe to drive with P02D3?+
Short-term yes, but the ECM can no longer trim cylinder 4's fueling correctly, so the engine may run rough. Get it repaired before it worsens.
Can I just clear P02D3?+
It returns once the learned offset hits its limit again. This reflects a real injector or circuit fault, not a passing glitch.
Related codes
Often seen with P02D3
Read & clear P02D3 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