P208C: Reductant Pump Control Circuit Low
The P208C code indicates that the powertrain control module (PCM) has detected a low voltage condition 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 exhaust stream to reduce NOx emissions. A low circuit voltage typically points to a wiring issue, a faulty pump, or a PCM problem. If left unaddressed, the vehicle may enter limp mode and fail emissions tests.
1. Most Common Causes
- Faulty reductant pump
- Open or shorted wiring in the pump control circuit
- Corroded or loose electrical connector
- 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 message
3. Step-by-Step Diagnosis
Step 1: Scan for additional codes and record freeze frame data.
Step 2: Visually inspect the reductant pump connector and wiring for damage, corrosion, or loose connections.
Step 3: Test the pump control circuit voltage at the PCM connector using a multimeter; compare to manufacturer specifications.
Step 4: If voltage is low, isolate the circuit by disconnecting the pump and checking for continuity and shorts.
Step 5: If wiring is intact, test the pump resistance and operation; replace if faulty.
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, reducing speed and drivability. Continued driving can also cause damage to the SCR system.
How much does it cost to fix?▼
The cost typically ranges from $50 to $150 for diagnosis and minor repairs like connector cleaning or wiring repair. If the pump needs replacement, parts and labor can add $200-$500.
5. Commonly Affected Makes
This is a generic OBD2 code, potentially applicable to any manufacturer using this diagnostic standard.