Exhaust Aftertreatment Fuel Injector Control Performance
The P20CC code indicates that the powertrain control module (PCM) has detected a performance issue with the exhaust aftertreatment fuel injector, which is used to inject fuel into the exhaust stream for diesel particulate filter (DPF) regeneration or selective catalytic reduction (SCR) system heating. This injector is critical for maintaining proper exhaust aftertreatment function. When the PCM detects that the injector is not operating within expected parameters—such as incorrect flow rate, electrical malfunction, or timing issues—it sets this code. Common causes include a faulty injector, wiring problems, or a defective PCM. Symptoms may include reduced fuel economy, illuminated check engine light, and potential DPF clogging.
1. Most Common Causes
- Faulty exhaust aftertreatment fuel injector
- Wiring or connector issues (open, short, corrosion)
- Defective powertrain control module (PCM)
2. Symptoms You Will Notice
- Check Engine Light illuminated
- Reduced fuel economy
- Possible DPF regeneration issues or clogging
3. Step-by-Step Diagnosis
Step 1: Use an OBD2 scanner to confirm the code and check for related codes (e.g., P20CE, P20CF).
Step 2: Visually inspect the injector wiring and connectors for damage, corrosion, or loose connections.
Step 3: Test the injector resistance and actuation using a multimeter and scan tool; compare to manufacturer specifications.
Step 4: If wiring and injector are okay, check PCM for software updates or faults; replace PCM if necessary.
4. Frequently Asked Questions
Is it safe to drive with this code?▼
It is not recommended to drive long distances as it can lead to DPF clogging and reduced engine performance. Short trips may be okay, but repair promptly.
How much does it cost to fix?▼
Diagnosis typically costs $50-$150. Injector replacement ranges from $200-$600, and PCM replacement can be $500-$1000.
5. Commonly Affected Makes
This is a generic OBD2 code, potentially applicable to any manufacturer using this diagnostic standard.