Exhaust Aftertreatment Fuel Supply Control Circuit/Open
The P20D7 code indicates a problem in the electrical circuit that controls the fuel supply to the exhaust aftertreatment system, typically used for diesel particulate filter regeneration or selective catalytic reduction. This circuit includes the fuel injector, wiring, and control module. An open circuit means there is a break in the electrical path, preventing the injector from operating. This can lead to incomplete regeneration, increased emissions, and potential damage to the aftertreatment system.
1. Most Common Causes
- Open or shorted wiring in the fuel supply control circuit
- Faulty fuel injector for aftertreatment system
- Corroded or loose electrical connectors
- Failed engine control module (ECM) or aftertreatment control module
2. Symptoms You Will Notice
- Check Engine Light illuminated
- Reduced fuel efficiency
- Increased exhaust emissions
- Possible regeneration issues (DPF not regenerating properly)
3. Step-by-Step Diagnosis
Step 1: Use a scan tool to confirm the code and check for related codes.
Step 2: Visually inspect the wiring and connectors for damage, corrosion, or loose connections.
Step 3: Test the fuel injector resistance and voltage supply using a multimeter.
Step 4: Check for continuity in the circuit between the injector and the control module.
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 incomplete regeneration, increased emissions, and potential damage to the aftertreatment system. Short trips may be possible but should be avoided until repaired.
How much does it cost to fix?▼
The cost typically ranges from $50 to $150 for diagnosis and repair, depending on the cause. If the injector needs replacement, parts can add $100-$300.
5. Commonly Affected Makes
This is a generic OBD2 code, potentially applicable to any manufacturer using this diagnostic standard.