Cylinder 5 Injector Circuit Low
The P0273 code indicates that the Engine Control Module (ECM) has detected a low voltage or current condition in the electrical circuit for the fuel injector on cylinder 5. This typically means the injector's resistance is too low, there is a short to ground, or the injector driver circuit is malfunctioning. The ECM monitors the injector circuit for proper voltage and current flow; when the signal falls below a specified threshold, it sets this code. This can lead to incomplete fuel delivery, causing misfires and reduced engine performance.
1. Most Common Causes
- Faulty fuel injector on cylinder 5 (internal short or low resistance)
- Short to ground in the injector wiring or connector
- Open or high resistance in the injector circuit
- Faulty ECM or injector driver circuit
2. Symptoms You Will Notice
- Engine misfire on cylinder 5
- Rough idle or hesitation during acceleration
- Check Engine Light illuminated
- Decreased fuel economy and power loss
3. Step-by-Step Diagnosis
Step 1: Use a scan tool to confirm the code and check for related codes (e.g., P0205 for injector circuit).
Step 2: Visually inspect the injector connector and wiring for damage, corrosion, or shorts.
Step 3: Measure the resistance of the cylinder 5 injector with a multimeter; compare to manufacturer specs (typically 12-16 ohms).
Step 4: Perform a continuity test on the injector circuit from the ECM to the injector connector.
Step 5: If wiring and injector are good, test the ECM output with a noid light or oscilloscope to verify the driver signal.
4. 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 further engine issues. Short trips to a repair shop are acceptable if the engine is not running rough.
How much does it cost to fix?▼
The cost typically ranges from $150 to $400, including parts and labor. A single injector replacement is around $100-$200, plus diagnostic time.
5. Commonly Affected Makes
This is a generic OBD2 code, potentially applicable to any manufacturer using this diagnostic standard.