Injector Circuit Malfunction - Cylinder 4
The P0204 code indicates a malfunction in the electrical circuit of the fuel injector for cylinder 4. This means the powertrain control module (PCM) has detected an abnormal voltage or resistance in the injector circuit, which can prevent the injector from opening properly. Common causes include a faulty injector, wiring issues, or a problem with the PCM. This can lead to misfires, poor fuel economy, and potential engine damage if not addressed.
01. Most Common Causes
- Faulty fuel injector on cylinder 4
- Open or shorted wiring in the injector circuit
- Poor electrical connection at the injector or PCM
- Failed PCM (rare)
02. Symptoms You Will Notice
- Check Engine Light illuminated
- Engine misfire or rough idle
- Reduced engine power and poor acceleration
- Increased fuel consumption
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 or corrosion.
Step 3: Use a multimeter to test injector resistance (should be 11-18 ohms).
Step 4: Check for power and ground at the injector connector with the engine running.
Step 5: Swap injector with another cylinder to see if the code follows.
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 it can cause misfires, catalytic converter damage, and reduced fuel economy. Short trips to a repair shop are okay.
How much does it cost to fix?▼
The cost typically ranges from $50 to $150 for diagnosis and repair, but replacing an injector can cost $200-$400 including parts and labor.