Reductant Pump Control Circuit Low
The P208C code indicates that the powertrain control module (PCM) has detected a low voltage condition in the reductant pump control circuit. This circuit controls the diesel exhaust fluid (DEF) pump, which injects DEF into the exhaust stream to reduce NOx emissions. A low voltage reading suggests a short to ground, open circuit, or faulty component in the pump control circuit, potentially affecting DEF delivery and emission system performance.
01. Most Common Causes
- Faulty reductant pump
- Open or shorted wiring in the pump control circuit
- Corroded or loose electrical connectors
- Failed PCM (rare)
02. Symptoms You Will Notice
- Check Engine Light illuminated
- Reduced engine performance or limp mode
- Increased diesel exhaust fluid consumption
- Failed emissions test
03. Step-by-Step Diagnosis
Step 1: Scan for codes and record freeze frame data.
Step 2: Visually inspect the reductant pump and wiring for damage or corrosion.
Step 3: Test the pump control circuit voltage with a multimeter; compare to manufacturer specs.
Step 4: Check continuity and resistance in the circuit; repair or replace as needed.
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 may lead to reduced engine performance, limp mode, or failed emissions. Short trips to a repair shop are generally safe.
How much does it cost to fix?▼
The cost typically ranges from $50 to $150 for diagnosis and minor repairs like wiring fixes. Pump replacement can cost $200-$500 or more.