Exhaust Aftertreatment Fuel Injector Stuck Open
The P20CF code indicates that the exhaust aftertreatment fuel injector, which injects fuel into the exhaust stream to regenerate the diesel particulate filter (DPF), is stuck in the open position. This causes continuous fuel flow into the exhaust, leading to excessive fuel consumption, potential damage to the DPF and catalytic converter, and increased emissions. The issue is commonly found in diesel engines with DPF systems.
01. Most Common Causes
- Faulty exhaust aftertreatment fuel injector
- Electrical short or open circuit in injector wiring
- Damaged injector driver circuit in the PCM
- Carbon buildup causing injector to stick open
02. Symptoms You Will Notice
- Check Engine Light illuminated
- Excessive fuel consumption
- Rough idle or engine misfire
- Black smoke from exhaust
- DPF regeneration issues
03. Step-by-Step Diagnosis
Step 1: Scan for codes and record freeze frame data.
Step 2: Visually inspect the injector and wiring for damage or corrosion.
Step 3: Test injector resistance with a multimeter (specs vary by manufacturer).
Step 4: Check for fuel leakage around the injector.
Step 5: Perform a bi-directional test to command the injector open/close and monitor response.
04. Commonly Affected Makes
05. Frequently Asked Questions
Is it safe to drive with this code?▼
Driving with P20CF is not recommended as it can cause severe damage to the DPF and catalytic converter, leading to costly repairs. It also increases fuel consumption and emissions.
How much does it cost to fix?▼
Repair costs typically range from $200 to $600, including parts and labor. The injector itself costs $100-$300, and labor adds $100-$300 depending on the vehicle.