Cylinder 1 Injector Data Incompatible
The P268C code indicates that the Engine Control Module (ECM) has detected a mismatch between the expected and actual data from the fuel injector on cylinder 1. This typically occurs when the injector's calibration data (e.g., flow rate, trim values) stored in the ECM does not match the physical injector installed, often after injector replacement without proper programming. It can also be caused by a faulty injector, wiring issues, or ECM software problems.
1. Most Common Causes
- Injector calibration code (IQA/QR) not programmed or incorrectly programmed in the PCM after replacement
- Wrong injector installed (part number different from original)
- Internal failure of cylinder 1 injector altering its hydraulic/electrical response
- Faulty PCM or memory corruption
- Damaged wiring or connector for injector 1 preventing verification
2. Symptoms You Will Notice
- Check Engine Light illuminated
- Engine misfire or rough idle
- Reduced fuel economy and performance
- Possible hard starting or stalling
3. Step-by-Step Diagnosis
Step 1: Scan the ECM for all codes and freeze frame data to confirm P268C and check for related codes.
Step 2: Inspect the wiring and connector at cylinder 1 injector for damage, corrosion, or loose pins.
Step 3: Use a scan tool to read the injector calibration data stored in the ECM and compare it to the injector part number installed.
Step 4: If injector was recently replaced, reprogram the ECM with the correct injector calibration data using a factory-level scan tool.
Step 5: If reprogramming fails, swap the injector with another cylinder to see if the code follows; if so, replace the injector.
4. Frequently Asked Questions
Is it safe to drive with this code?▼
It is not recommended to drive long distances as the engine may run poorly, cause misfires, and potentially damage the catalytic converter. Short trips to a repair shop are acceptable.
How much does it cost to fix?▼
The cost typically ranges from $50 to $150 for diagnosis and ECM reprogramming. If injector replacement is needed, it can cost $200-$400 per injector plus labor.
5. Commonly Affected Makes
This is a generic OBD2 code, potentially applicable to any manufacturer using this diagnostic standard.