Cylinder 4 Fuel Injector Offset Learning at Min Limit
The P02D2 code indicates that the Engine Control Module (ECM) has detected the fuel injector offset learning for cylinder 4 has reached its minimum adaptive limit. This means the ECM is unable to further adjust the fuel trim for that cylinder, often due to a rich condition caused by a leaking or stuck-open injector, low fuel pressure, or a mechanical issue. The offset learning is part of the fuel trim adaptation process to maintain proper air-fuel ratio.
01. Most Common Causes
- Faulty or leaking fuel injector on cylinder 4
- Low fuel pressure or clogged fuel filter
- Engine mechanical issue (low compression, worn piston rings, etc.)
- Wiring or connector issue at injector 4
02. Symptoms You Will Notice
- Check Engine Light illuminated
- Rough idle or misfire on cylinder 4
- Poor fuel economy
- Possible hesitation or lack of power
03. Step-by-Step Diagnosis
Step 1: Scan for additional codes and check freeze frame data.
Step 2: Perform a fuel injector balance test to isolate cylinder 4.
Step 3: Check fuel pressure and volume; inspect fuel filter.
Step 4: Inspect injector 4 wiring and connector for damage.
Step 5: Perform a compression test on cylinder 4 to rule out mechanical issues.
04. Commonly Affected Makes
05. Frequently Asked Questions
Is it safe to drive with this code?▼
It is not recommended to drive long distances as it can cause catalytic converter damage due to unburned fuel. Short trips to a repair shop are acceptable.
How much does it cost to fix?▼
Diagnosis typically costs $50-$150. Injector replacement ranges from $200-$600 per injector including labor, depending on vehicle make and model.