P20D6 - Exhaust Aftertreatment Fuel Injector Stuck Closed
The P20D6 code indicates that the powertrain control module (PCM) has detected that the exhaust aftertreatment fuel injector, used for diesel particulate filter (DPF) regeneration, is stuck in the closed position. This prevents fuel from being injected into the exhaust stream to raise temperatures for regeneration, leading to potential DPF clogging and reduced engine performance.
01. Most Common Causes
- Faulty exhaust aftertreatment fuel injector
- Wiring or connector issues in the injector circuit
- Clogged or restricted fuel supply to the injector
- PCM software or hardware malfunction
02. Symptoms You Will Notice
- Illuminated check engine light
- Reduced fuel economy
- Decreased engine power
- DPF regeneration failure or frequent regeneration attempts
03. Step-by-Step Diagnosis
Step 1: Scan for additional codes and freeze frame data to understand conditions when code set.
Step 2: Visually inspect the exhaust aftertreatment fuel injector and its wiring/connectors for damage or corrosion.
Step 3: Test the injector's electrical resistance and compare to manufacturer specifications.
Step 4: Check fuel pressure and supply to the injector; ensure no blockages.
Step 5: If all else is okay, replace the exhaust aftertreatment fuel injector and clear codes.
04. Commonly Affected Makes
05. Frequently Asked Questions
Is it safe to drive with this code?▼
It is not recommended to drive long distances with this code, as it can lead to a clogged DPF and costly repairs. Short trips may be okay, but immediate diagnosis is advised.
How much does it cost to fix?▼
The cost typically ranges from $150 to $400, including parts and labor. The injector itself costs $50-$150, and labor adds $100-$250 depending on the vehicle.