Cylinder 7 Injector Circuit Low
The P0279 code indicates that the Engine Control Module (ECM) has detected a low voltage or resistance condition in the electrical circuit for the fuel injector on cylinder 7. This typically means the injector's electrical circuit is shorted to ground, has an open circuit, or the injector itself has failed internally. The ECM monitors the injector driver circuit and when the voltage is lower than expected during operation, it sets this code. This can cause a misfire, reduced power, and increased emissions.
01. Most Common Causes
- Faulty fuel injector on cylinder 7 (internal short or open)
- Wiring or connector issues (shorted to ground, open, or high resistance)
- ECM internal fault (rare)
02. Symptoms You Will Notice
- Check Engine Light illuminated
- Engine misfire or rough idle
- Reduced engine power and poor acceleration
- Increased fuel consumption and emissions
03. Step-by-Step Diagnosis
Step 1: Scan for codes and record freeze frame data.
Step 2: Visually inspect the injector connector and wiring for damage, corrosion, or loose connections.
Step 3: Measure resistance of cylinder 7 injector; compare to specification (typically 12-16 ohms).
Step 4: Check for voltage at injector connector with key on; should see battery voltage on one pin.
Step 5: Perform a continuity test from injector connector to ECM; check for shorts to ground or power.
Step 6: If wiring and injector are good, suspect ECM failure (rare).
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 the misfire can damage the catalytic converter and cause poor performance. Short trips to a repair shop are okay.
How much does it cost to fix?▼
Costs vary: injector replacement $150-$400, wiring repair $100-$300, ECM replacement $500-$1000. Diagnosis fee is typically $100-$150.