P0408 Volkswagen Code - Exhaust Gas Recirculation Sensor 'B' Circuit High
Quick Answer
This Diagnostic Trouble Code (DTC) is stored in the Engine Control Module (ECM) when a fault is detected with the exhaust gas recirculation position sensor. Common causes include Faulty Exhaust Gas Recirculation (EGR) Control Solenoid Valve, Faulty Exhaust Gas Recirculation Lift Sensor, Exhaust Gas Recirculation Lift Sensor harness is open or shorted. Severity is Moderate - service should be scheduled soon. The vehicle may still be drivable for short trips if it runs normally, but avoid hard driving and repair it soon.
- What it means
- P0408 Volkswagen indicates Exhaust Gas Recirculation Sensor 'B' Circuit High.
- Common causes
- Common causes include Faulty Exhaust Gas Recirculation (EGR) Control Solenoid Valve, Faulty Exhaust Gas Recirculation Lift Sensor, Exhaust Gas Recirculation Lift Sensor harness is open or shorted.
- Severity
- Moderate - service should be scheduled soon.
- Can I drive?
- The vehicle may still be drivable for short trips if it runs normally, but avoid hard driving and repair it soon.
Code P0408 Volkswagen Description
1. Mass airflow meter signal, the quantity of fresh air entering the engine will reduce proportionally as the exhaust gas entering the cylinder increases.
2. Manifold absolute pressure sensor signal, the pressure in the intake manifold will be altered depending on the introduction of exhaust gases. Comparatively higher pressure will exist when exhaust gases are recycled.
3. Exhaust gas differential pressure sensor, this component measures the pressure differential across two points to validate flow.
4. Wideband oxygen sensors, the signal from these sensors can be used to monitor the oxygen content in the exhaust gas.
What are the Possible Causes of the DTC P0408 Volkswagen?
- Faulty Exhaust Gas Recirculation (EGR) Control Solenoid Valve
- Faulty Exhaust Gas Recirculation Lift Sensor
- Exhaust Gas Recirculation Lift Sensor harness is open or shorted
- Exhaust Gas Recirculation Lift Sensor circuit poor electrical connection
- Faulty Engine Control Module (ECM)
How to Fix the DTC P0408 Volkswagen?
Review the 'Possible Causes' above and visually examine the corresponding wiring harness and connectors. Check for damaged components and inspect connector pins for signs of being broken, bent, pushed out, or corroded.
What is the Cost to Diagnose the Code?
Labor: 1.0
To diagnose the P0408 Volkswagen code, it typically requires 1.0 hour of labor. Rates vary by location, vehicle, and shop. Many shops charge between $80–$150 per hour; dealerships and metro areas may be higher, independents may be lower.
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Frequently Asked Questions about P0408 Volkswagen Code
1. What are common symptoms of OBDII code P0408 in a Volkswagen?
- Common symptoms include rough idling, reduced engine performance, and the illumination of the Check Engine Light.
2. What does the OBDII code P0408 indicate in a Volkswagen?
- OBDII code P0408 indicates a problem with the Exhaust Gas Recirculation (EGR) Sensor 'B' Circuit registering a high voltage.
3. What are the possible causes of OBDII code P0408 in a Volkswagen?
- Possible causes include a faulty EGR sensor, damaged wiring or connectors in the EGR sensor circuit, or a problem with the EGR valve itself.
4. Can driving with OBDII code P0408 in a Volkswagen cause further damage?
- Continuing to drive with this code may lead to poor fuel economy, increased emissions, and potential damage to other engine components over time.
5. How can I diagnose and repair OBDII code P0408 in my Volkswagen?
- Diagnosing and repairing this code usually involves testing the EGR sensor, inspecting the wiring and connectors, and checking the EGR valve for proper operation.
6. Is it safe to drive my Volkswagen with OBDII code P0408?
- It is generally not recommended to drive with this code present, as it can lead to decreased engine performance and potential damage if left unresolved.
7. Can a DIY enthusiast fix OBDII code P0408 in a Volkswagen?
- Depending on your skill level and access to tools, a DIY enthusiast may be able to diagnose and repair this code by following a repair manual or online guides.
8. How much does it typically cost to repair OBDII code P0408 in a Volkswagen?
- The cost of repairing this code can vary depending on the specific issue, but it may range from $100 to $300 for parts and labor at a repair shop.
9. Will resetting the Check Engine Light resolve OBDII code P0408 in a Volkswagen?
- Simply resetting the Check Engine Light will not fix the underlying issue causing OBDII code P0408; proper diagnosis and repairs are necessary to resolve it.
10. How often does OBDII code P0408 occur in Volkswagen vehicles?
- While not extremely common, OBDII code P0408 can still occur in Volkswagen vehicles, especially in older models or those with high mileage.
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