Cylinder 3 Injector Circuit High
The P0268 code indicates that the Engine Control Module (ECM) has detected a high voltage or resistance in the electrical circuit of the fuel injector for cylinder 3. This typically means the injector circuit is drawing more current than expected, often due to a short to power, a faulty injector with low internal resistance, or a wiring issue. The ECM monitors the injector driver circuit and sets this code when the voltage or current exceeds the calibrated threshold.
1. Most Common Causes
- Cylinder 3 injector damaged or internal coil shorted
- Injector wiring shorted to voltage
- Injector connector with corroded or bent terminals
- Injector internal resistance out of specification
- Internal failure in the engine control module (ECM/PCM)
- Issue in the voltage supply line to the injector
2. Symptoms You Will Notice
- Engine misfire or rough idle
- Check Engine Light illuminated
- Reduced engine power and poor fuel economy
- Possible fuel smell from exhaust
3. Step-by-Step Diagnosis
Step 1: Scan for codes and record freeze frame data.
Step 2: Visually inspect the injector wiring and connector for damage, corrosion, or shorts.
Step 3: Measure resistance of cylinder 3 injector and compare to specification (typically 12-16 ohms).
Step 4: Check for voltage at the injector connector with key on; should be battery voltage on one pin.
Step 5: Perform a injector balance test or use a noid light to verify injector pulse.
Step 6: If wiring and injector are okay, test the ECM output or swap injectors to isolate the issue.
4. Frequently Asked Questions
Is it safe to drive with this code?▼
It is not recommended to drive for extended periods as it can cause engine misfire, catalytic converter damage, and poor performance. Have it diagnosed promptly.
How much does it cost to fix?▼
The cost varies: injector replacement is $150-$400 including labor; wiring repairs are $100-$250; ECM replacement is $500-$1000. Diagnosis fee is typically $100-$150.
5. Commonly Affected Makes
This is a generic OBD2 code, potentially applicable to any manufacturer using this diagnostic standard.