Cylinder 4 Injector Circuit/Open
The controller detected a fault, including a possible open circuit, in the injector circuit for cylinder 4. This identifies an electrical monitoring problem rather than proving that the injector is clogged or must be replaced. Wiring, connectors, supply and the driver require assessment. Locate cylinder 4 using the manufacturer diagram; gasoline and diesel injector tests are not interchangeable.
Can I keep driving?
Fuel odor, visible leakage, severe shaking, stalling or a flashing light call for a safe stop, engine shutdown and towing. Do not restart if a leak is suspected. Even without symptoms, get shop guidance before further driving.
Flashing light, burning smell or smoke? Pull over safely. Danger to life: call 911.
What does this code mean for your car?
The same code can need different checks depending on the model and engine. Enter your vehicle details to find relevant sources and checks.
Symptoms
- Shaking from uneven cylinder 4 contribution
- Low power or hesitation
- Steady or flashing check engine light
Possible causes
- 1Open or short in cylinder 4 injector wiring
- 2Poor contact or connector corrosion
- 3Electrical fault inside the injector
- 4Power supply or controller driver problem
These possibilities are not ranked by frequency and do not diagnose your vehicle.
Checks you can safely do yourself
Safe checks only: engine off and cold, car on level ground.
- Save the code and freeze-frame data if your scanner offers them, without clearing anything.
- Look for a cylinder 4 misfire code in the scan report without disconnecting an injector or commanding injection.
When you need a shop
Stop safely if shaking or a flashing light occurs. The shop should identify cylinder 4, test its injector circuit and driver, and use the injection-system-specific procedure before selecting parts.
How much does it cost?
A US repair estimate needs a diagnosis and a local shop quote.
No verified US repair quote is available for this fault. The price depends on diagnosis, vehicle, parts and local labor; request 2-3 itemized quotes.
Get 2-3 quotes
Investigate this code for my carFAQ
Can I keep driving with P0204?
Fuel odor, visible leakage, severe shaking, stalling or a flashing light call for a safe stop, engine shutdown and towing. Do not restart if a leak is suspected. Even without symptoms, get shop guidance before further driving.
What can cause P0204?
Possible causes include open or short in cylinder 4 injector wiring; poor contact or connector corrosion; electrical fault inside the injector; power supply or controller driver problem. These are diagnostic possibilities, not a confirmed diagnosis or a parts shopping list.
Does clearing the code fix the problem?
No. Clearing a code does not repair the problem or prove that no fault exists. It may erase useful evidence and reset readiness monitors. Save codes and freeze-frame data first; confirming a repair requires the vehicle-specific checks.
What if this code appears during a used-car inspection?
Arrange an independent professional pre-purchase inspection before committing. Request a complete scan, readiness status and diagnosis of the relevant system. Get written findings and a repair estimate; an unlit warning lamp does not replace inspection.
How much does a P0204 repair cost?
No verified US repair quote is available for this fault. The price depends on diagnosis, vehicle, parts and local labor; request 2-3 itemized quotes.