P02D4
Cylinder 5 Fuel Injector A Offset Learning At Min Limit
Fuel injector control
Generic OBD-II
High
What it means
P02D4 means the module's learned fuel-offset correction for the cylinder-5 injector has hit its minimum allowed limit — it can't trim the injector any lower to keep it balanced with the others. This usually points to a worn injector, a wiring/connection issue, or a control-module supply problem. Often the check-engine light is the main symptom, though the cylinder may run slightly rough.
High
Can I keep driving? Often the only sign is the warning light, though cylinder 5 may run slightly rough; the engine keeps running, but have the injector and its control circuit checked.
Common symptoms
What you'll notice
- Check-engine light on
- Slightly rough idle or minor power loss (may be unnoticeable)
- Cylinder-5 injector balance/contribution fault logged
- Occasional hesitation
Common causes
Most likely first
- Worn or out-of-tolerance injector on cylinder 5 needing more correction than allowedLikely
- Poor connection or open/shorted wiring at the injector control circuitCommon
- Faulty injector control module (FICM) supply or groundCommon
- Injector deposits or fuel-quality issues skewing the learned offsetLess often
How to diagnose & fix
Work through it in order
- Read freeze-frame data and review the cylinder-5 injector offset/balance values.
- Inspect the injector connector and wiring for a poor connection, open, or short.
- Check the injector control module (FICM) supply voltage and ground circuits.
- Test the cylinder-5 injector against the others; clean or replace it if out of tolerance.
- Clear the learned values and re-run the relearn, then re-test.
FAQ
Quick answers
Is it safe to drive with P02D4?+
Usually yes for short trips — it's a fuel-injector learning limit, not a no-start. But a drifting injector can worsen, so have it diagnosed.
Can I just clear P02D4?+
It returns once the offset again hits its minimum limit. The injector or its control circuit needs correcting first.
Related codes
Often seen with P02D4
Read & clear P02D4 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