Exhaust Aftertreatment Fuel Injector Control Performance
The P20D2 code indicates that the powertrain control module (PCM) has detected a performance issue with the exhaust aftertreatment fuel injector control circuit. This injector is used to introduce fuel into the exhaust stream for regeneration of the diesel particulate filter (DPF) or to raise exhaust temperature for selective catalytic reduction (SCR) systems. The PCM monitors the injector's electrical circuit and fuel delivery performance; if the actual performance deviates from expected parameters, this code is set. Common causes include a faulty injector, wiring issues, or a malfunctioning PCM.
1. Most Common Causes
- Faulty exhaust aftertreatment fuel injector
- Open or shorted wiring in the injector control circuit
- Poor electrical connection at the injector or PCM
- Failed PCM (rare)
2. Symptoms You Will Notice
- Illuminated check engine light
- Reduced fuel efficiency
- Possible DPF regeneration issues or excessive soot buildup
- Engine may enter limp mode
3. Step-by-Step Diagnosis
Step 1: Use an OBD2 scanner to confirm the code and check for related codes (e.g., P20D0-P20D9).
Step 2: Visually inspect the injector and wiring harness for damage, corrosion, or loose connections.
Step 3: Test the injector resistance with a multimeter (specs vary by vehicle; typically 0.5-2 ohms).
Step 4: Check for proper voltage and ground at the injector connector with the key on.
Step 5: If wiring and injector are okay, test the PCM output using a scan tool to command the injector on/off.
4. Frequently Asked Questions
Is it safe to drive with this code?▼
It is not recommended to drive long distances. The issue can lead to incomplete DPF regeneration, causing clogging and potential damage to the exhaust system. You may experience reduced performance and fuel economy.
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 accessibility.
5. Commonly Affected Makes
This is a generic OBD2 code, potentially applicable to any manufacturer using this diagnostic standard.