Cylinder 7 Injector Circuit High
The P0280 code indicates that the Engine Control Module (ECM) has detected a high voltage or resistance in the electrical circuit for the fuel injector on cylinder 7. This can be caused by a faulty injector, damaged wiring, poor connections, or a short to voltage. The ECM monitors the injector circuit for proper voltage and current; when the signal is out of range, it sets this code.
1. Most Common Causes
- Faulty fuel injector on cylinder 7
- Short to voltage in injector wiring
- Open or high resistance in injector circuit
- Damaged connector or poor pin contact
- ECM failure (rare)
2. Symptoms You Will Notice
- Engine misfire on cylinder 7
- Rough idle or hesitation
- Check Engine Light illuminated
- Reduced fuel economy
- Possible engine knocking
3. Step-by-Step Diagnosis
Step 1: Scan for codes and record freeze frame data.
Step 2: Visually inspect injector connector and wiring for damage or corrosion.
Step 3: Measure resistance of cylinder 7 injector (typically 12-16 ohms) and compare to other cylinders.
Step 4: Check for voltage at 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 confirm injector pulse.
Step 6: If wiring and injector are good, test ECM output or swap injector to see if code follows.
4. Frequently Asked Questions
Is it safe to drive with this code?▼
It is not recommended to drive long distances as it can cause misfire, catalytic converter damage, and poor performance. Short trips to a repair shop are okay.
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.
5. Commonly Affected Makes
This is a generic OBD2 code, potentially applicable to any manufacturer using this diagnostic standard.