First thing you need to do is have the engine control module software updated if one is available. The leak detection pump uses current to measure the evap leak. As the leak detection pump ages, it consumes more current and that is why it may be setting off a false evap leak code. The software makes some sensor calibrations but also changes how the leak detection works. The solution? A new functionality has been developed which uses a new method to accurately diagnose the leakage status of the tank system, independent of any fluctuations or aging in the DMTL or other components. This new method calculates the pressure in the tank and the mass air flow through the fixed displacement pump and uses these values together with the common gas law to make an accurate calculation of the actual leak size. You may want to call Volvo to see if the Engine Management Software is covered by the 10 year/150k mile extended warranty. Once the software is installed if one is available, have them run the evap test leak to see if it passes. If it does, problem solved. If it failes and you did replace the cap, there is no damage around the filler neck, and you smoked the evap system and found system has no leaks, then replace the leak detection pump. Good luck and hope this information helps you out. ;)
Oct 21, 2010 at 1:12 AM
