Constant oscillation of the solenoid regulator valve in the bore creates wear, which can reduce solenoid feed pressure, resulting in various shift complaints in VW/Audi 096, 097, 098, 01M, 01N, 01P units. In addition, wear at the solenoid regulator valve can reduce balance line pressure at the main regulator valve, which will result in low line pressure or no line rise. Sonnax oversized solenoid regulator valve 119940-06K restores solenoid feed oil pressure. Adjustment of the ratcheting end plug on the boost regulator valve may be needed after servicing the solenoid regulator valve. Sonnax recommends the adjustment tool 119940-TL9 for proper adjustment without damage to the plug.
Vacuum testing at the port(s) indicated fails to hold the recommended minimum in-Hg, or if wear is visually detected.