Exhaust Aftertreatment Fuel Supply Control Circuit High
The P20DA code indicates that the powertrain control module (PCM) has detected a high voltage condition in the exhaust aftertreatment fuel supply control circuit. This circuit controls the fuel injector that delivers diesel exhaust fluid (DEF) or fuel for regeneration in the diesel particulate filter (DPF). A high voltage reading typically points to a short to power, a faulty injector, or a wiring issue.
1. Most Common Causes
- Short to power in the fuel supply control circuit wiring
- Faulty exhaust aftertreatment fuel injector
- Damaged or corroded connector
- Failed PCM (rare)
2. Symptoms You Will Notice
- Check Engine Light illuminated
- Reduced fuel economy
- Possible regeneration issues or DPF clogging
- Engine may enter limp mode
3. Step-by-Step Diagnosis
Step 1: Scan for additional codes and freeze frame data.
Step 2: Visually inspect the fuel injector and wiring harness for damage or corrosion.
Step 3: Use a multimeter to check for voltage at the injector connector; compare to manufacturer specs.
Step 4: Test the injector resistance; replace if out of range.
Step 5: If wiring and injector are okay, check PCM output and ground circuits.
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 further damage. Short trips may be possible but should be avoided.
How much does it cost to fix?▼
Repair costs typically range from $150 to $400, depending on whether the injector or wiring needs replacement.
5. Commonly Affected Makes
This is a generic OBD2 code, potentially applicable to any manufacturer using this diagnostic standard.