Reductant Pump Control Circuit/Open
The P208A code indicates that the powertrain control module (PCM) has detected an open or malfunction in the control circuit of the reductant pump, which is part of the selective catalytic reduction (SCR) system. This pump delivers diesel exhaust fluid (DEF) to the SCR catalyst to reduce NOx emissions. An open circuit means there is a break in the electrical path, preventing the pump from operating correctly. This can lead to increased emissions and potential derating of engine performance.
01. Most Common Causes
- Blown fuse or faulty relay for the reductant pump
- Open or shorted wiring in the pump control circuit
- Faulty reductant pump motor
- Corroded or damaged electrical connectors
02. Symptoms You Will Notice
- Illuminated check engine light
- Reduced engine power or derating
- Increased exhaust emissions
- Possible DEF warning message on dashboard
03. 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 fuse and relay; replace if blown.
Step 3: Check the wiring and connectors for damage, corrosion, or loose connections.
Step 4: Test the pump motor resistance and voltage supply using a multimeter.
Step 5: If all else is good, replace the reductant pump.
04. Commonly Affected Makes
05. Frequently Asked Questions
Is it safe to drive with this code?▼
It is not recommended to drive long distances with this code, as it can cause the engine to enter a derated mode, reducing power and potentially leading to further emissions system damage.
How much does it cost to fix?▼
The cost to fix P208A typically ranges from $50 to $150 for parts and labor, depending on whether it's a simple fuse replacement or a pump replacement.