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 the powertrain control module (PCM). An open circuit means there is a break in the electrical path, preventing proper fuel delivery for aftertreatment processes, which can lead to increased emissions and potential damage to the exhaust system.
01. Most Common Causes
- Open or shorted wiring in the fuel supply control circuit
- Faulty fuel injector for aftertreatment
- Corroded or damaged connectors
- Failed PCM or aftertreatment control module
02. Symptoms You Will Notice
- Check Engine Light illuminated
- Reduced fuel economy
- Increased exhaust emissions
- Possible regeneration issues or DPF clogging
03. Step-by-Step Diagnosis
Step 1: Use a scan tool to retrieve freeze frame data and confirm the code.
Step 2: Visually inspect the wiring and connectors for damage, corrosion, or loose connections.
Step 3: Test the fuel injector resistance and compare to manufacturer specs.
Step 4: Check for voltage and ground at the injector connector using a multimeter.
Step 5: If wiring and injector are okay, test the PCM output or replace the control module.
04. Commonly Affected Makes
05. 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 increased emissions. Short trips may be possible, but repair should be done promptly.
How much does it cost to fix?▼
The cost typically ranges from $50 to $150 for diagnosis and simple wiring repairs, but could be higher if the injector or PCM needs replacement.