P2171 Fault Code

Exhaust Pressure Regulator Vent Solenoid Control Circuit High

• What does that mean?
• Symptoms
• Causes
• Solutions

The P2171 fault code indicates a problem with the exhaust pressure regulator vent solenoid control circuit. This code typically appears when the engine control module (ECM) detects a higher-than-normal voltage or resistance in the solenoid circuit. The exhaust pressure regulator helps manage the exhaust gas recirculation (EGR) system, ensuring optimal engine performance and emissions control.

What are the symptoms of the P2171 code?

Symptoms associated with the P2171 fault code may include:

• Illuminated Check Engine Light (CEL)
• Poor acceleration or engine performance
• Increased emissions or failure of emissions tests
• Unusual exhaust sounds or odors
• Engine stalling or rough idle due to improper air-fuel mixture

What causes the P2171 code?

Common causes of the P2171 code include:

• Faulty exhaust pressure regulator vent solenoid
• Wiring issues such as shorts, open circuits, or corrosion in the solenoid circuit
• ECM malfunction or programming issues
• Vacuum leaks affecting the EGR system performance
• Malfunctioning EGR valve leading to incorrect pressure readings

How to fix P2171?

To resolve the P2171 fault code, the following steps should be taken:

1. Inspect the wiring and connectors for the exhaust pressure regulator vent solenoid for damage, corrosion, or loose connections.
2. Test the solenoid for proper functionality, and replace it if it is faulty.
3. Check for vacuum leaks in the EGR system and repair any found.
4. If necessary, reprogram or replace the ECM based on diagnostic results.
5. Clear the fault code and perform a road test to ensure the issue is resolved.