Reductant Pump Control Circuit High
The P208D code indicates that the powertrain control module (PCM) has detected a high voltage condition in the reductant pump control circuit. This pump is responsible for delivering diesel exhaust fluid (DEF) to the selective catalytic reduction (SCR) system to reduce NOx emissions. A high voltage reading suggests a short to power, faulty pump, or wiring issue, which can prevent proper DEF injection and lead to increased emissions.
1. Most Common Causes
- Short to power in the reductant pump control circuit
- Faulty reductant pump
- Corroded or damaged wiring/connectors
- Failed PCM (rare)
2. Symptoms You Will Notice
- Check Engine Light illuminated
- Reduced engine performance or limp mode
- Increased NOx emissions
- Possible DEF system warning messages
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 reductant pump wiring and connectors for damage, corrosion, or shorts.
Step 3: Test the pump control circuit voltage with a multimeter; compare to manufacturer specs.
Step 4: If circuit voltage is high, isolate the short by disconnecting components and re-testing.
Step 5: Replace the reductant pump if it fails resistance or operation tests.
4. Frequently Asked Questions
Is it safe to drive with this code?▼
It is not recommended to drive long distances as the vehicle may enter limp mode and emissions will be high. Short trips to a repair shop are acceptable.
How much does it cost to fix?▼
Diagnosis typically costs $50-$150. Replacing the reductant pump can range from $200-$600 including parts and labor.
5. Commonly Affected Makes
This is a generic OBD2 code, potentially applicable to any manufacturer using this diagnostic standard.