P05D9

Symptoms

• Check Engine Light Is On
• Unstable idle
• Oil leakage through seals and gaskets
• Oily air filter or air filter housing
• Smoke from engine breather
• Increased oil consumption

Causes

• Short circuit of the PCV valve control wire to the vehicle body
• Oil contamination of the connector causing contact shorting
• Internal short in PCV regulator valve coil
• Mechanical damage to wiring insulation in high temperature zones
• Overcurrent due to charring of valve winding

How to Fix

1. Read all fault codes, record related codes
2. Disconnect the PCV valve connector and check if the code goes away - if so, the problem is in the valve itself
3. Measure the resistance of the valve winding: when closed it will be close to zero
4. Inspect the connector and wiring for oil contamination, melted insulation, and traces of corrosion.
5. Test the control wire from the ECU to the valve for a short to ground.
6. Replace the PCV regulator valve and re-insulate the wiring if necessary.

Related codes

Error P05D9 by Vehicle Brand